diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java
index 8b1d60b..e55bb16 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java
@@ -19,7 +19,7 @@
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
-import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
+import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
 
@@ -41,6 +41,7 @@
  *
  * TODO: Remove calls from classes except Ver3DictDecoder
  * TODO: Move this file to makedict/internal.
+ * TODO: Rename this class to DictDecoderUtils.
  */
 public final class BinaryDictDecoderUtils {
 
@@ -213,7 +214,7 @@
                     buffer[index++] = (byte)(0xFF & codePoint);
                 }
             }
-            buffer[index++] = FormatSpec.GROUP_CHARACTERS_TERMINATOR;
+            buffer[index++] = FormatSpec.PTNODE_CHARACTERS_TERMINATOR;
             return index - origin;
         }
 
@@ -237,7 +238,7 @@
                     buffer.write((byte) (0xFF & codePoint));
                 }
             }
-            buffer.write(FormatSpec.GROUP_CHARACTERS_TERMINATOR);
+            buffer.write(FormatSpec.PTNODE_CHARACTERS_TERMINATOR);
         }
 
         /**
@@ -264,7 +265,7 @@
         static int readChar(final DictBuffer dictBuffer) {
             int character = dictBuffer.readUnsignedByte();
             if (!fitsOnOneByte(character)) {
-                if (FormatSpec.GROUP_CHARACTERS_TERMINATOR == character) {
+                if (FormatSpec.PTNODE_CHARACTERS_TERMINATOR == character) {
                     return FormatSpec.INVALID_CHARACTER;
                 }
                 character <<= 16;
@@ -295,14 +296,14 @@
             }
         }
         int address;
-        switch (optionFlags & FormatSpec.MASK_GROUP_ADDRESS_TYPE) {
-            case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_ONEBYTE:
+        switch (optionFlags & FormatSpec.MASK_CHILDREN_ADDRESS_TYPE) {
+            case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE:
                 return dictBuffer.readUnsignedByte();
-            case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_TWOBYTES:
+            case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES:
                 return dictBuffer.readUnsignedShort();
-            case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_THREEBYTES:
+            case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES:
                 return dictBuffer.readUnsignedInt24();
-            case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_NOADDRESS:
+            case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS:
             default:
                 return FormatSpec.NO_CHILDREN_ADDRESS;
         }
@@ -320,14 +321,14 @@
     }
 
     /**
-     * Reads and returns the char group count out of a buffer and forwards the pointer.
+     * Reads and returns the PtNode count out of a buffer and forwards the pointer.
      */
-    public static int readCharGroupCount(final DictBuffer dictBuffer) {
+    public static int readPtNodeCount(final DictBuffer dictBuffer) {
         final int msb = dictBuffer.readUnsignedByte();
-        if (FormatSpec.MAX_CHARGROUPS_FOR_ONE_BYTE_CHARGROUP_COUNT >= msb) {
+        if (FormatSpec.MAX_PTNODES_FOR_ONE_BYTE_PTNODE_COUNT >= msb) {
             return msb;
         } else {
-            return ((FormatSpec.MAX_CHARGROUPS_FOR_ONE_BYTE_CHARGROUP_COUNT & msb) << 8)
+            return ((FormatSpec.MAX_PTNODES_FOR_ONE_BYTE_PTNODE_COUNT & msb) << 8)
                     + dictBuffer.readUnsignedByte();
         }
     }
@@ -369,18 +370,18 @@
         final StringBuilder builder = new StringBuilder();
         // the length of the path from the root to the leaf is limited by MAX_WORD_LENGTH
         for (int count = 0; count < FormatSpec.MAX_WORD_LENGTH; ++count) {
-            CharGroupInfo currentInfo;
+            PtNodeInfo currentInfo;
             int loopCounter = 0;
             do {
                 dictBuffer.position(currentPos);
                 currentInfo = dictDecoder.readPtNode(currentPos, options);
-                if (BinaryDictIOUtils.isMovedGroup(currentInfo.mFlags, options)) {
+                if (BinaryDictIOUtils.isMovedPtNode(currentInfo.mFlags, options)) {
                     currentPos = currentInfo.mParentAddress + currentInfo.mOriginalAddress;
                 }
                 if (DBG && loopCounter++ > MAX_JUMPS) {
                     MakedictLog.d("Too many jumps - probably a bug");
                 }
-            } while (BinaryDictIOUtils.isMovedGroup(currentInfo.mFlags, options));
+            } while (BinaryDictIOUtils.isMovedPtNode(currentInfo.mFlags, options));
             if (Integer.MIN_VALUE == frequency) frequency = currentInfo.mFrequency;
             builder.insert(0,
                     new String(currentInfo.mCharacters, 0, currentInfo.mCharacters.length));
@@ -395,14 +396,14 @@
             final FormatOptions options) {
         final DictBuffer dictBuffer = dictDecoder.getDictBuffer();
         dictBuffer.position(headerSize);
-        final int count = readCharGroupCount(dictBuffer);
-        int groupPos = headerSize + BinaryDictIOUtils.getGroupCountSize(count);
+        final int count = readPtNodeCount(dictBuffer);
+        int groupPos = headerSize + BinaryDictIOUtils.getPtNodeCountSize(count);
         final StringBuilder builder = new StringBuilder();
         WeightedString result = null;
 
-        CharGroupInfo last = null;
+        PtNodeInfo last = null;
         for (int i = count - 1; i >= 0; --i) {
-            CharGroupInfo info = dictDecoder.readPtNode(groupPos, options);
+            PtNodeInfo info = dictDecoder.readPtNode(groupPos, options);
             groupPos = info.mEndAddress;
             if (info.mOriginalAddress == pos) {
                 builder.append(new String(info.mCharacters, 0, info.mCharacters.length));
@@ -414,8 +415,8 @@
                     if (null == last) continue;
                     builder.append(new String(last.mCharacters, 0, last.mCharacters.length));
                     dictBuffer.position(last.mChildrenAddress);
-                    i = readCharGroupCount(dictBuffer);
-                    groupPos = last.mChildrenAddress + BinaryDictIOUtils.getGroupCountSize(i);
+                    i = readPtNodeCount(dictBuffer);
+                    groupPos = last.mChildrenAddress + BinaryDictIOUtils.getPtNodeCountSize(i);
                     last = null;
                     continue;
                 }
@@ -424,8 +425,8 @@
             if (0 == i && BinaryDictIOUtils.hasChildrenAddress(last.mChildrenAddress)) {
                 builder.append(new String(last.mCharacters, 0, last.mCharacters.length));
                 dictBuffer.position(last.mChildrenAddress);
-                i = readCharGroupCount(dictBuffer);
-                groupPos = last.mChildrenAddress + BinaryDictIOUtils.getGroupCountSize(i);
+                i = readPtNodeCount(dictBuffer);
+                groupPos = last.mChildrenAddress + BinaryDictIOUtils.getPtNodeCountSize(i);
                 last = null;
                 continue;
             }
@@ -444,25 +445,25 @@
      * @param dictDecoder the dict decoder, correctly positioned at the start of a node array.
      * @param headerSize the size, in bytes, of the file header.
      * @param reverseNodeArrayMap a mapping from addresses to already read node arrays.
-     * @param reverseGroupMap a mapping from addresses to already read character groups.
+     * @param reversePtNodeMap a mapping from addresses to already read PtNodes.
      * @param options file format options.
      * @return the read node array with all his children already read.
      */
     private static PtNodeArray readNodeArray(final Ver3DictDecoder dictDecoder,
             final int headerSize, final Map<Integer, PtNodeArray> reverseNodeArrayMap,
-            final Map<Integer, CharGroup> reverseGroupMap, final FormatOptions options)
+            final Map<Integer, PtNode> reversePtNodeMap, final FormatOptions options)
             throws IOException {
         final DictBuffer dictBuffer = dictDecoder.getDictBuffer();
-        final ArrayList<CharGroup> nodeArrayContents = new ArrayList<CharGroup>();
+        final ArrayList<PtNode> nodeArrayContents = new ArrayList<PtNode>();
         final int nodeArrayOriginPos = dictBuffer.position();
 
         do { // Scan the linked-list node.
             final int nodeArrayHeadPos = dictBuffer.position();
-            final int count = readCharGroupCount(dictBuffer);
-            int groupOffsetPos = nodeArrayHeadPos + BinaryDictIOUtils.getGroupCountSize(count);
-            for (int i = count; i > 0; --i) { // Scan the array of CharGroup.
-                CharGroupInfo info = dictDecoder.readPtNode(groupOffsetPos, options);
-                if (BinaryDictIOUtils.isMovedGroup(info.mFlags, options)) continue;
+            final int count = readPtNodeCount(dictBuffer);
+            int groupOffsetPos = nodeArrayHeadPos + BinaryDictIOUtils.getPtNodeCountSize(count);
+            for (int i = count; i > 0; --i) { // Scan the array of PtNode.
+                PtNodeInfo info = dictDecoder.readPtNode(groupOffsetPos, options);
+                if (BinaryDictIOUtils.isMovedPtNode(info.mFlags, options)) continue;
                 ArrayList<WeightedString> shortcutTargets = info.mShortcutTargets;
                 ArrayList<WeightedString> bigrams = null;
                 if (null != info.mBigrams) {
@@ -482,17 +483,17 @@
                         final int currentPosition = dictBuffer.position();
                         dictBuffer.position(info.mChildrenAddress);
                         children = readNodeArray(dictDecoder, headerSize, reverseNodeArrayMap,
-                                reverseGroupMap, options);
+                                reversePtNodeMap, options);
                         dictBuffer.position(currentPosition);
                     }
                     nodeArrayContents.add(
-                            new CharGroup(info.mCharacters, shortcutTargets, bigrams,
+                            new PtNode(info.mCharacters, shortcutTargets, bigrams,
                                     info.mFrequency,
                                     0 != (info.mFlags & FormatSpec.FLAG_IS_NOT_A_WORD),
                                     0 != (info.mFlags & FormatSpec.FLAG_IS_BLACKLISTED), children));
                 } else {
                     nodeArrayContents.add(
-                            new CharGroup(info.mCharacters, shortcutTargets, bigrams,
+                            new PtNode(info.mCharacters, shortcutTargets, bigrams,
                                     info.mFrequency,
                                     0 != (info.mFlags & FormatSpec.FLAG_IS_NOT_A_WORD),
                                     0 != (info.mFlags & FormatSpec.FLAG_IS_BLACKLISTED)));
@@ -566,9 +567,9 @@
         final FileHeader fileHeader = dictDecoder.readHeader();
 
         Map<Integer, PtNodeArray> reverseNodeArrayMapping = new TreeMap<Integer, PtNodeArray>();
-        Map<Integer, CharGroup> reverseGroupMapping = new TreeMap<Integer, CharGroup>();
+        Map<Integer, PtNode> reversePtNodeMapping = new TreeMap<Integer, PtNode>();
         final PtNodeArray root = readNodeArray(dictDecoder, fileHeader.mHeaderSize,
-                reverseNodeArrayMapping, reverseGroupMapping, fileHeader.mFormatOptions);
+                reverseNodeArrayMapping, reversePtNodeMapping, fileHeader.mFormatOptions);
 
         FusionDictionary newDict = new FusionDictionary(root, fileHeader.mDictionaryOptions);
         if (null != dict) {
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java
index 40effb5..b95db21 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java
@@ -18,7 +18,7 @@
 
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
-import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
+import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
@@ -33,6 +33,8 @@
  * Encodes binary files for a FusionDictionary.
  *
  * All the methods in this class are static.
+ *
+ * TODO: Rename this class to DictEncoderUtils.
  */
 public class BinaryDictEncoderUtils {
 
@@ -58,46 +60,46 @@
      * @param characters the character array
      * @return the size of the char array, including the terminator if any
      */
-    static int getGroupCharactersSize(final int[] characters) {
+    static int getPtNodeCharactersSize(final int[] characters) {
         int size = CharEncoding.getCharArraySize(characters);
-        if (characters.length > 1) size += FormatSpec.GROUP_TERMINATOR_SIZE;
+        if (characters.length > 1) size += FormatSpec.PTNODE_TERMINATOR_SIZE;
         return size;
     }
 
     /**
-     * Compute the binary size of the character array in a group
+     * Compute the binary size of the character array in a PtNode
      *
      * If only one character, this is the size of this character. If many, it's the sum of their
      * sizes + 1 byte for the terminator.
      *
-     * @param group the group
+     * @param ptNode the PtNode
      * @return the size of the char array, including the terminator if any
      */
-    private static int getGroupCharactersSize(final CharGroup group) {
-        return getGroupCharactersSize(group.mChars);
+    private static int getPtNodeCharactersSize(final PtNode ptNode) {
+        return getPtNodeCharactersSize(ptNode.mChars);
     }
 
     /**
-     * Compute the binary size of the group count for a node array.
+     * Compute the binary size of the PtNode count for a node array.
      * @param nodeArray the nodeArray
-     * @return the size of the group count, either 1 or 2 bytes.
+     * @return the size of the PtNode count, either 1 or 2 bytes.
      */
-    private static int getGroupCountSize(final PtNodeArray nodeArray) {
-        return BinaryDictIOUtils.getGroupCountSize(nodeArray.mData.size());
+    private static int getPtNodeCountSize(final PtNodeArray nodeArray) {
+        return BinaryDictIOUtils.getPtNodeCountSize(nodeArray.mData.size());
     }
 
     /**
      * Compute the size of a shortcut in bytes.
      */
     private static int getShortcutSize(final WeightedString shortcut) {
-        int size = FormatSpec.GROUP_ATTRIBUTE_FLAGS_SIZE;
+        int size = FormatSpec.PTNODE_ATTRIBUTE_FLAGS_SIZE;
         final String word = shortcut.mWord;
         final int length = word.length();
         for (int i = 0; i < length; i = word.offsetByCodePoints(i, 1)) {
             final int codePoint = word.codePointAt(i);
             size += CharEncoding.getCharSize(codePoint);
         }
-        size += FormatSpec.GROUP_TERMINATOR_SIZE;
+        size += FormatSpec.PTNODE_TERMINATOR_SIZE;
         return size;
     }
 
@@ -109,7 +111,7 @@
      */
     static int getShortcutListSize(final ArrayList<WeightedString> shortcutList) {
         if (null == shortcutList || shortcutList.isEmpty()) return 0;
-        int size = FormatSpec.GROUP_SHORTCUT_LIST_SIZE_SIZE;
+        int size = FormatSpec.PTNODE_SHORTCUT_LIST_SIZE_SIZE;
         for (final WeightedString shortcut : shortcutList) {
             size += getShortcutSize(shortcut);
         }
@@ -117,60 +119,60 @@
     }
 
     /**
-     * Compute the maximum size of a CharGroup, assuming 3-byte addresses for everything.
+     * Compute the maximum size of a PtNode, assuming 3-byte addresses for everything.
      *
-     * @param group the CharGroup to compute the size of.
+     * @param ptNode the PtNode to compute the size of.
      * @param options file format options.
-     * @return the maximum size of the group.
+     * @return the maximum size of the PtNode.
      */
-    private static int getCharGroupMaximumSize(final CharGroup group, final FormatOptions options) {
-        int size = getGroupHeaderSize(group, options);
+    private static int getPtNodeMaximumSize(final PtNode ptNode, final FormatOptions options) {
+        int size = getNodeHeaderSize(ptNode, options);
         // If terminal, one byte for the frequency
-        if (group.isTerminal()) size += FormatSpec.GROUP_FREQUENCY_SIZE;
-        size += FormatSpec.GROUP_MAX_ADDRESS_SIZE; // For children address
-        size += getShortcutListSize(group.mShortcutTargets);
-        if (null != group.mBigrams) {
-            size += (FormatSpec.GROUP_ATTRIBUTE_FLAGS_SIZE
-                    + FormatSpec.GROUP_ATTRIBUTE_MAX_ADDRESS_SIZE)
-                    * group.mBigrams.size();
+        if (ptNode.isTerminal()) size += FormatSpec.PTNODE_FREQUENCY_SIZE;
+        size += FormatSpec.PTNODE_MAX_ADDRESS_SIZE; // For children address
+        size += getShortcutListSize(ptNode.mShortcutTargets);
+        if (null != ptNode.mBigrams) {
+            size += (FormatSpec.PTNODE_ATTRIBUTE_FLAGS_SIZE
+                    + FormatSpec.PTNODE_ATTRIBUTE_MAX_ADDRESS_SIZE)
+                    * ptNode.mBigrams.size();
         }
         return size;
     }
 
     /**
-     * Compute the maximum size of each node of a node array, assuming 3-byte addresses for
+     * Compute the maximum size of each PtNode of a PtNode array, assuming 3-byte addresses for
      * everything, and caches it in the `mCachedSize' member of the nodes; deduce the size of
      * the containing node array, and cache it it its 'mCachedSize' member.
      *
-     * @param nodeArray the node array to compute the maximum size of.
+     * @param ptNodeArray the node array to compute the maximum size of.
      * @param options file format options.
      */
-    private static void calculateNodeArrayMaximumSize(final PtNodeArray nodeArray,
+    private static void calculatePtNodeArrayMaximumSize(final PtNodeArray ptNodeArray,
             final FormatOptions options) {
-        int size = getGroupCountSize(nodeArray);
-        for (CharGroup g : nodeArray.mData) {
-            final int groupSize = getCharGroupMaximumSize(g, options);
-            g.mCachedSize = groupSize;
-            size += groupSize;
+        int size = getPtNodeCountSize(ptNodeArray);
+        for (PtNode node : ptNodeArray.mData) {
+            final int nodeSize = getPtNodeMaximumSize(node, options);
+            node.mCachedSize = nodeSize;
+            size += nodeSize;
         }
         if (options.mSupportsDynamicUpdate) {
             size += FormatSpec.FORWARD_LINK_ADDRESS_SIZE;
         }
-        nodeArray.mCachedSize = size;
+        ptNodeArray.mCachedSize = size;
     }
 
     /**
-     * Compute the size of the header (flag + [parent address] + characters size) of a CharGroup.
+     * Compute the size of the header (flag + [parent address] + characters size) of a PtNode.
      *
-     * @param group the group of which to compute the size of the header
+     * @param ptNode the PtNode of which to compute the size of the header
      * @param options file format options.
      */
-    private static int getGroupHeaderSize(final CharGroup group, final FormatOptions options) {
+    private static int getNodeHeaderSize(final PtNode ptNode, final FormatOptions options) {
         if (BinaryDictIOUtils.supportsDynamicUpdate(options)) {
-            return FormatSpec.GROUP_FLAGS_SIZE + FormatSpec.PARENT_ADDRESS_SIZE
-                    + getGroupCharactersSize(group);
+            return FormatSpec.PTNODE_FLAGS_SIZE + FormatSpec.PARENT_ADDRESS_SIZE
+                    + getPtNodeCharactersSize(ptNode);
         } else {
-            return FormatSpec.GROUP_FLAGS_SIZE + getGroupCharactersSize(group);
+            return FormatSpec.PTNODE_FLAGS_SIZE + getPtNodeCharactersSize(ptNode);
         }
     }
 
@@ -203,14 +205,14 @@
     // cache performance and dictionary size.
     /* package for tests */ static ArrayList<PtNodeArray> flattenTree(
             final PtNodeArray rootNodeArray) {
-        final int treeSize = FusionDictionary.countCharGroups(rootNodeArray);
+        final int treeSize = FusionDictionary.countPtNodes(rootNodeArray);
         MakedictLog.i("Counted nodes : " + treeSize);
         final ArrayList<PtNodeArray> flatTree = new ArrayList<PtNodeArray>(treeSize);
         return flattenTreeInner(flatTree, rootNodeArray);
     }
 
     private static ArrayList<PtNodeArray> flattenTreeInner(final ArrayList<PtNodeArray> list,
-            final PtNodeArray nodeArray) {
+            final PtNodeArray ptNodeArray) {
         // Removing the node is necessary if the tails are merged, because we would then
         // add the same node several times when we only want it once. A number of places in
         // the code also depends on any node being only once in the list.
@@ -228,11 +230,11 @@
         // this simple list.remove operation O(n*n) overall. On Android this overhead is very
         // high.
         // For future reference, the code to remove duplicate is a simple : list.remove(node);
-        list.add(nodeArray);
-        final ArrayList<CharGroup> branches = nodeArray.mData;
+        list.add(ptNodeArray);
+        final ArrayList<PtNode> branches = ptNodeArray.mData;
         final int nodeSize = branches.size();
-        for (CharGroup group : branches) {
-            if (null != group.mChildren) flattenTreeInner(list, group.mChildren);
+        for (PtNode ptNode : branches) {
+            if (null != ptNode.mChildren) flattenTreeInner(list, ptNode.mChildren);
         }
         return list;
     }
@@ -248,7 +250,7 @@
      * from the new position in the current node array to the new position in the target node
      * array.
      *
-     * @param currentNodeArray node array containing the CharGroup where the offset will be written
+     * @param currentNodeArray node array containing the PtNode where the offset will be written
      * @param offsetFromStartOfCurrentNodeArray offset, in bytes, from the start of currentNodeArray
      * @param targetNodeArray the target node array to get the offset to
      * @return the offset to the target node array
@@ -269,20 +271,20 @@
     }
 
     /**
-     * Get the offset from a position inside a current node array to a target CharGroup, during
+     * Get the offset from a position inside a current node array to a target PtNode, during
      * update.
      *
-     * @param currentNodeArray node array containing the CharGroup where the offset will be written
+     * @param currentNodeArray node array containing the PtNode where the offset will be written
      * @param offsetFromStartOfCurrentNodeArray offset, in bytes, from the start of currentNodeArray
-     * @param targetCharGroup the target CharGroup to get the offset to
-     * @return the offset to the target CharGroup
+     * @param targetPtNode the target PtNode to get the offset to
+     * @return the offset to the target PtNode
      */
     // TODO: is there any way to factorize this method with the one above?
-    private static int getOffsetToTargetCharGroupDuringUpdate(final PtNodeArray currentNodeArray,
-            final int offsetFromStartOfCurrentNodeArray, final CharGroup targetCharGroup) {
+    private static int getOffsetToTargetPtNodeDuringUpdate(final PtNodeArray currentNodeArray,
+            final int offsetFromStartOfCurrentNodeArray, final PtNode targetPtNode) {
         final int oldOffsetBasePoint = currentNodeArray.mCachedAddressBeforeUpdate
                 + offsetFromStartOfCurrentNodeArray;
-        final boolean isTargetBeforeCurrent = (targetCharGroup.mCachedAddressBeforeUpdate
+        final boolean isTargetBeforeCurrent = (targetPtNode.mCachedAddressBeforeUpdate
                 < oldOffsetBasePoint);
         // If the target is before the current node array, then its address has already been
         // updated. We can use the AfterUpdate member, and compare it to our own member after
@@ -292,9 +294,9 @@
         if (isTargetBeforeCurrent) {
             final int newOffsetBasePoint = currentNodeArray.mCachedAddressAfterUpdate
                     + offsetFromStartOfCurrentNodeArray;
-            return targetCharGroup.mCachedAddressAfterUpdate - newOffsetBasePoint;
+            return targetPtNode.mCachedAddressAfterUpdate - newOffsetBasePoint;
         } else {
-            return targetCharGroup.mCachedAddressBeforeUpdate - oldOffsetBasePoint;
+            return targetPtNode.mCachedAddressBeforeUpdate - oldOffsetBasePoint;
         }
     }
 
@@ -308,49 +310,49 @@
      * contents (as in, any of the addresses stored in the cache fields) have changed with
      * respect to their previous value.
      *
-     * @param nodeArray the node array to compute the size of.
+     * @param ptNodeArray the node array to compute the size of.
      * @param dict the dictionary in which the word/attributes are to be found.
      * @param formatOptions file format options.
      * @return false if none of the cached addresses inside the node array changed, true otherwise.
      */
-    private static boolean computeActualNodeArraySize(final PtNodeArray nodeArray,
+    private static boolean computeActualPtNodeArraySize(final PtNodeArray ptNodeArray,
             final FusionDictionary dict, final FormatOptions formatOptions) {
         boolean changed = false;
-        int size = getGroupCountSize(nodeArray);
-        for (CharGroup group : nodeArray.mData) {
-            group.mCachedAddressAfterUpdate = nodeArray.mCachedAddressAfterUpdate + size;
-            if (group.mCachedAddressAfterUpdate != group.mCachedAddressBeforeUpdate) {
+        int size = getPtNodeCountSize(ptNodeArray);
+        for (PtNode ptNode : ptNodeArray.mData) {
+            ptNode.mCachedAddressAfterUpdate = ptNodeArray.mCachedAddressAfterUpdate + size;
+            if (ptNode.mCachedAddressAfterUpdate != ptNode.mCachedAddressBeforeUpdate) {
                 changed = true;
             }
-            int groupSize = getGroupHeaderSize(group, formatOptions);
-            if (group.isTerminal()) groupSize += FormatSpec.GROUP_FREQUENCY_SIZE;
-            if (null == group.mChildren && formatOptions.mSupportsDynamicUpdate) {
-                groupSize += FormatSpec.SIGNED_CHILDREN_ADDRESS_SIZE;
-            } else if (null != group.mChildren) {
+            int nodeSize = getNodeHeaderSize(ptNode, formatOptions);
+            if (ptNode.isTerminal()) nodeSize += FormatSpec.PTNODE_FREQUENCY_SIZE;
+            if (null == ptNode.mChildren && formatOptions.mSupportsDynamicUpdate) {
+                nodeSize += FormatSpec.SIGNED_CHILDREN_ADDRESS_SIZE;
+            } else if (null != ptNode.mChildren) {
                 if (formatOptions.mSupportsDynamicUpdate) {
-                    groupSize += FormatSpec.SIGNED_CHILDREN_ADDRESS_SIZE;
+                    nodeSize += FormatSpec.SIGNED_CHILDREN_ADDRESS_SIZE;
                 } else {
-                    groupSize += getByteSize(getOffsetToTargetNodeArrayDuringUpdate(nodeArray,
-                            groupSize + size, group.mChildren));
+                    nodeSize += getByteSize(getOffsetToTargetNodeArrayDuringUpdate(ptNodeArray,
+                            nodeSize + size, ptNode.mChildren));
                 }
             }
-            groupSize += getShortcutListSize(group.mShortcutTargets);
-            if (null != group.mBigrams) {
-                for (WeightedString bigram : group.mBigrams) {
-                    final int offset = getOffsetToTargetCharGroupDuringUpdate(nodeArray,
-                            groupSize + size + FormatSpec.GROUP_FLAGS_SIZE,
+            nodeSize += getShortcutListSize(ptNode.mShortcutTargets);
+            if (null != ptNode.mBigrams) {
+                for (WeightedString bigram : ptNode.mBigrams) {
+                    final int offset = getOffsetToTargetPtNodeDuringUpdate(ptNodeArray,
+                            nodeSize + size + FormatSpec.PTNODE_FLAGS_SIZE,
                             FusionDictionary.findWordInTree(dict.mRootNodeArray, bigram.mWord));
-                    groupSize += getByteSize(offset) + FormatSpec.GROUP_FLAGS_SIZE;
+                    nodeSize += getByteSize(offset) + FormatSpec.PTNODE_FLAGS_SIZE;
                 }
             }
-            group.mCachedSize = groupSize;
-            size += groupSize;
+            ptNode.mCachedSize = nodeSize;
+            size += nodeSize;
         }
         if (formatOptions.mSupportsDynamicUpdate) {
             size += FormatSpec.FORWARD_LINK_ADDRESS_SIZE;
         }
-        if (nodeArray.mCachedSize != size) {
-            nodeArray.mCachedSize = size;
+        if (ptNodeArray.mCachedSize != size) {
+            ptNodeArray.mCachedSize = size;
             changed = true;
         }
         return changed;
@@ -363,19 +365,19 @@
      * @param formatOptions file format options.
      * @return the byte size of the entire stack.
      */
-    private static int initializeNodeArraysCachedAddresses(final ArrayList<PtNodeArray> flatNodes,
+    private static int initializePtNodeArraysCachedAddresses(final ArrayList<PtNodeArray> flatNodes,
             final FormatOptions formatOptions) {
         int nodeArrayOffset = 0;
         for (final PtNodeArray nodeArray : flatNodes) {
             nodeArray.mCachedAddressBeforeUpdate = nodeArrayOffset;
-            int groupCountSize = getGroupCountSize(nodeArray);
-            int groupOffset = 0;
-            for (final CharGroup g : nodeArray.mData) {
-                g.mCachedAddressBeforeUpdate = g.mCachedAddressAfterUpdate =
-                        groupCountSize + nodeArrayOffset + groupOffset;
-                groupOffset += g.mCachedSize;
+            int nodeCountSize = getPtNodeCountSize(nodeArray);
+            int nodeffset = 0;
+            for (final PtNode ptNode : nodeArray.mData) {
+                ptNode.mCachedAddressBeforeUpdate = ptNode.mCachedAddressAfterUpdate =
+                        nodeCountSize + nodeArrayOffset + nodeffset;
+                nodeffset += ptNode.mCachedSize;
             }
-            final int nodeSize = groupCountSize + groupOffset
+            final int nodeSize = nodeCountSize + nodeffset
                     + (formatOptions.mSupportsDynamicUpdate
                             ? FormatSpec.FORWARD_LINK_ADDRESS_SIZE : 0);
             nodeArrayOffset += nodeArray.mCachedSize;
@@ -388,11 +390,11 @@
      *
      * @param flatNodes the list of node arrays.
      */
-    private static void updateNodeArraysCachedAddresses(final ArrayList<PtNodeArray> flatNodes) {
+    private static void updatePtNodeArraysCachedAddresses(final ArrayList<PtNodeArray> flatNodes) {
         for (final PtNodeArray nodeArray : flatNodes) {
             nodeArray.mCachedAddressBeforeUpdate = nodeArray.mCachedAddressAfterUpdate;
-            for (final CharGroup g : nodeArray.mData) {
-                g.mCachedAddressBeforeUpdate = g.mCachedAddressAfterUpdate;
+            for (final PtNode ptNode : nodeArray.mData) {
+                ptNode.mCachedAddressBeforeUpdate = ptNode.mCachedAddressAfterUpdate;
             }
         }
     }
@@ -407,38 +409,38 @@
      */
     private static void computeParentAddresses(final ArrayList<PtNodeArray> flatNodes) {
         for (final PtNodeArray nodeArray : flatNodes) {
-            for (final CharGroup group : nodeArray.mData) {
-                if (null != group.mChildren) {
+            for (final PtNode ptNode : nodeArray.mData) {
+                if (null != ptNode.mChildren) {
                     // Assign my address to children's parent address
                     // Here BeforeUpdate and AfterUpdate addresses have the same value, so it
                     // does not matter which we use.
-                    group.mChildren.mCachedParentAddress = group.mCachedAddressAfterUpdate
-                            - group.mChildren.mCachedAddressAfterUpdate;
+                    ptNode.mChildren.mCachedParentAddress = ptNode.mCachedAddressAfterUpdate
+                            - ptNode.mChildren.mCachedAddressAfterUpdate;
                 }
             }
         }
     }
 
     /**
-     * Compute the addresses and sizes of an ordered list of node arrays.
+     * Compute the addresses and sizes of an ordered list of PtNode arrays.
      *
-     * This method takes a list of node arrays and will update their cached address and size
+     * This method takes a list of PtNode arrays and will update their cached address and size
      * values so that they can be written into a file. It determines the smallest size each of the
-     * nodes arrays can be given the addresses of its children and attributes, and store that into
-     * each node.
-     * The order of the node is given by the order of the array. This method makes no effort
+     * PtNode arrays can be given the addresses of its children and attributes, and store that into
+     * each PtNode.
+     * The order of the PtNode is given by the order of the array. This method makes no effort
      * to find a good order; it only mechanically computes the size this order results in.
      *
      * @param dict the dictionary
-     * @param flatNodes the ordered list of nodes arrays
+     * @param flatNodes the ordered list of PtNode arrays
      * @param formatOptions file format options.
      * @return the same array it was passed. The nodes have been updated for address and size.
      */
     private static ArrayList<PtNodeArray> computeAddresses(final FusionDictionary dict,
             final ArrayList<PtNodeArray> flatNodes, final FormatOptions formatOptions) {
         // First get the worst possible sizes and offsets
-        for (final PtNodeArray n : flatNodes) calculateNodeArrayMaximumSize(n, formatOptions);
-        final int offset = initializeNodeArraysCachedAddresses(flatNodes, formatOptions);
+        for (final PtNodeArray n : flatNodes) calculatePtNodeArrayMaximumSize(n, formatOptions);
+        final int offset = initializePtNodeArraysCachedAddresses(flatNodes, formatOptions);
 
         MakedictLog.i("Compressing the array addresses. Original size : " + offset);
         MakedictLog.i("(Recursively seen size : " + offset + ")");
@@ -447,19 +449,20 @@
         boolean changesDone = false;
         do {
             changesDone = false;
-            int nodeArrayStartOffset = 0;
-            for (final PtNodeArray nodeArray : flatNodes) {
-                nodeArray.mCachedAddressAfterUpdate = nodeArrayStartOffset;
-                final int oldNodeArraySize = nodeArray.mCachedSize;
-                final boolean changed = computeActualNodeArraySize(nodeArray, dict, formatOptions);
-                final int newNodeArraySize = nodeArray.mCachedSize;
+            int ptNodeArrayStartOffset = 0;
+            for (final PtNodeArray ptNodeArray : flatNodes) {
+                ptNodeArray.mCachedAddressAfterUpdate = ptNodeArrayStartOffset;
+                final int oldNodeArraySize = ptNodeArray.mCachedSize;
+                final boolean changed =
+                        computeActualPtNodeArraySize(ptNodeArray, dict, formatOptions);
+                final int newNodeArraySize = ptNodeArray.mCachedSize;
                 if (oldNodeArraySize < newNodeArraySize) {
                     throw new RuntimeException("Increased size ?!");
                 }
-                nodeArrayStartOffset += newNodeArraySize;
+                ptNodeArrayStartOffset += newNodeArraySize;
                 changesDone |= changed;
             }
-            updateNodeArraysCachedAddresses(flatNodes);
+            updatePtNodeArraysCachedAddresses(flatNodes);
             ++passes;
             if (passes > MAX_PASSES) throw new RuntimeException("Too many passes - probably a bug");
         } while (changesDone);
@@ -467,10 +470,10 @@
         if (formatOptions.mSupportsDynamicUpdate) {
             computeParentAddresses(flatNodes);
         }
-        final PtNodeArray lastNodeArray = flatNodes.get(flatNodes.size() - 1);
+        final PtNodeArray lastPtNodeArray = flatNodes.get(flatNodes.size() - 1);
         MakedictLog.i("Compression complete in " + passes + " passes.");
         MakedictLog.i("After address compression : "
-                + (lastNodeArray.mCachedAddressAfterUpdate + lastNodeArray.mCachedSize));
+                + (lastPtNodeArray.mCachedAddressAfterUpdate + lastPtNodeArray.mCachedSize));
 
         return flatNodes;
     }
@@ -478,25 +481,26 @@
     /**
      * Sanity-checking method.
      *
-     * This method checks a list of node arrays for juxtaposition, that is, it will do
+     * This method checks a list of PtNode arrays for juxtaposition, that is, it will do
      * nothing if each node array's cached address is actually the previous node array's address
      * plus the previous node's size.
      * If this is not the case, it will throw an exception.
      *
      * @param arrays the list of node arrays to check
      */
-    private static void checkFlatNodeArrayList(final ArrayList<PtNodeArray> arrays) {
+    private static void checkFlatPtNodeArrayList(final ArrayList<PtNodeArray> arrays) {
         int offset = 0;
         int index = 0;
-        for (final PtNodeArray nodeArray : arrays) {
+        for (final PtNodeArray ptNodeArray : arrays) {
             // BeforeUpdate and AfterUpdate addresses are the same here, so it does not matter
             // which we use.
-            if (nodeArray.mCachedAddressAfterUpdate != offset) {
+            if (ptNodeArray.mCachedAddressAfterUpdate != offset) {
                 throw new RuntimeException("Wrong address for node " + index
-                        + " : expected " + offset + ", got " + nodeArray.mCachedAddressAfterUpdate);
+                        + " : expected " + offset + ", got " +
+                        ptNodeArray.mCachedAddressAfterUpdate);
             }
             ++index;
-            offset += nodeArray.mCachedSize;
+            offset += ptNodeArray.mCachedSize;
         }
     }
 
@@ -552,19 +556,19 @@
     }
 
     /**
-     * Makes the flag value for a char group.
+     * Makes the flag value for a PtNode.
      *
-     * @param hasMultipleChars whether the group has multiple chars.
-     * @param isTerminal whether the group is terminal.
+     * @param hasMultipleChars whether the PtNode has multiple chars.
+     * @param isTerminal whether the PtNode is terminal.
      * @param childrenAddressSize the size of a children address.
-     * @param hasShortcuts whether the group has shortcuts.
-     * @param hasBigrams whether the group has bigrams.
-     * @param isNotAWord whether the group is not a word.
-     * @param isBlackListEntry whether the group is a blacklist entry.
+     * @param hasShortcuts whether the PtNode has shortcuts.
+     * @param hasBigrams whether the PtNode has bigrams.
+     * @param isNotAWord whether the PtNode is not a word.
+     * @param isBlackListEntry whether the PtNode is a blacklist entry.
      * @param formatOptions file format options.
      * @return the flags
      */
-    static int makeCharGroupFlags(final boolean hasMultipleChars, final boolean isTerminal,
+    static int makePtNodeFlags(final boolean hasMultipleChars, final boolean isTerminal,
             final int childrenAddressSize, final boolean hasShortcuts, final boolean hasBigrams,
             final boolean isNotAWord, final boolean isBlackListEntry,
             final FormatOptions formatOptions) {
@@ -576,16 +580,16 @@
         } else if (true) {
             switch (childrenAddressSize) {
                 case 1:
-                    flags |= FormatSpec.FLAG_GROUP_ADDRESS_TYPE_ONEBYTE;
+                    flags |= FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE;
                     break;
                 case 2:
-                    flags |= FormatSpec.FLAG_GROUP_ADDRESS_TYPE_TWOBYTES;
+                    flags |= FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES;
                     break;
                 case 3:
-                    flags |= FormatSpec.FLAG_GROUP_ADDRESS_TYPE_THREEBYTES;
+                    flags |= FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES;
                     break;
                 case 0:
-                    flags |= FormatSpec.FLAG_GROUP_ADDRESS_TYPE_NOADDRESS;
+                    flags |= FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS;
                     break;
                 default:
                     throw new RuntimeException("Node with a strange address");
@@ -598,12 +602,12 @@
         return flags;
     }
 
-    private static byte makeCharGroupFlags(final CharGroup group, final int groupAddress,
+    private static byte makePtNodeFlags(final PtNode node, final int ptNodeAddress,
             final int childrenOffset, final FormatOptions formatOptions) {
-        return (byte) makeCharGroupFlags(group.mChars.length > 1, group.mFrequency >= 0,
+        return (byte) makePtNodeFlags(node.mChars.length > 1, node.mFrequency >= 0,
                 getByteSize(childrenOffset),
-                group.mShortcutTargets != null && !group.mShortcutTargets.isEmpty(),
-                group.mBigrams != null, group.mIsNotAWord, group.mIsBlacklistEntry, formatOptions);
+                node.mShortcutTargets != null && !node.mShortcutTargets.isEmpty(),
+                node.mBigrams != null, node.mIsNotAWord, node.mIsBlacklistEntry, formatOptions);
     }
 
     /**
@@ -618,17 +622,17 @@
      */
     private static final int makeBigramFlags(final boolean more, final int offset,
             int bigramFrequency, final int unigramFrequency, final String word) {
-        int bigramFlags = (more ? FormatSpec.FLAG_ATTRIBUTE_HAS_NEXT : 0)
-                + (offset < 0 ? FormatSpec.FLAG_ATTRIBUTE_OFFSET_NEGATIVE : 0);
+        int bigramFlags = (more ? FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT : 0)
+                + (offset < 0 ? FormatSpec.FLAG_BIGRAM_ATTR_OFFSET_NEGATIVE : 0);
         switch (getByteSize(offset)) {
         case 1:
-            bigramFlags |= FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE;
+            bigramFlags |= FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE;
             break;
         case 2:
-            bigramFlags |= FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES;
+            bigramFlags |= FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_TWOBYTES;
             break;
         case 3:
-            bigramFlags |= FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES;
+            bigramFlags |= FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_THREEBYTES;
             break;
         default:
             throw new RuntimeException("Strange offset size");
@@ -673,7 +677,7 @@
         // small over-estimation that we get in this case. TODO: actually remove this bigram
         // if discretizedFrequency < 0.
         final int finalBigramFrequency = discretizedFrequency > 0 ? discretizedFrequency : 0;
-        bigramFlags += finalBigramFrequency & FormatSpec.FLAG_ATTRIBUTE_FREQUENCY;
+        bigramFlags += finalBigramFrequency & FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY;
         return bigramFlags;
     }
 
@@ -698,8 +702,8 @@
      * @return the flags
      */
     static final int makeShortcutFlags(final boolean more, final int frequency) {
-        return (more ? FormatSpec.FLAG_ATTRIBUTE_HAS_NEXT : 0)
-                + (frequency & FormatSpec.FLAG_ATTRIBUTE_FREQUENCY);
+        return (more ? FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT : 0)
+                + (frequency & FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY);
     }
 
     private static final int writeParentAddress(final byte[] buffer, final int index,
@@ -722,68 +726,69 @@
     }
 
     /**
-     * Write a node array to memory. The node array is expected to have its final position cached.
+     * Write a PtNodeArray to memory. The PtNodeArray is expected to have its final position cached.
      *
      * @param dict the dictionary the node array is a part of (for relative offsets).
      * @param buffer the memory buffer to write to.
-     * @param nodeArray the node array to write.
+     * @param ptNodeArray the node array to write.
      * @param formatOptions file format options.
      * @return the address of the END of the node.
      */
     @SuppressWarnings("unused")
     private static int writePlacedNode(final FusionDictionary dict, byte[] buffer,
-            final PtNodeArray nodeArray, final FormatOptions formatOptions) {
-        // TODO: Make the code in common with BinaryDictIOUtils#writeCharGroup
-        int index = nodeArray.mCachedAddressAfterUpdate;
+            final PtNodeArray ptNodeArray, final FormatOptions formatOptions) {
+        // TODO: Make the code in common with BinaryDictIOUtils#writePtNode
+        int index = ptNodeArray.mCachedAddressAfterUpdate;
 
-        final int groupCount = nodeArray.mData.size();
-        final int countSize = getGroupCountSize(nodeArray);
-        final int parentAddress = nodeArray.mCachedParentAddress;
+        final int ptNodeCount = ptNodeArray.mData.size();
+        final int countSize = getPtNodeCountSize(ptNodeArray);
+        final int parentAddress = ptNodeArray.mCachedParentAddress;
         if (1 == countSize) {
-            buffer[index++] = (byte)groupCount;
+            buffer[index++] = (byte)ptNodeCount;
         } else if (2 == countSize) {
             // We need to signal 2-byte size by setting the top bit of the MSB to 1, so
             // we | 0x80 to do this.
-            buffer[index++] = (byte)((groupCount >> 8) | 0x80);
-            buffer[index++] = (byte)(groupCount & 0xFF);
+            buffer[index++] = (byte)((ptNodeCount >> 8) | 0x80);
+            buffer[index++] = (byte)(ptNodeCount & 0xFF);
         } else {
             throw new RuntimeException("Strange size from getGroupCountSize : " + countSize);
         }
-        int groupAddress = index;
-        for (int i = 0; i < groupCount; ++i) {
-            final CharGroup group = nodeArray.mData.get(i);
-            if (index != group.mCachedAddressAfterUpdate) {
+        int ptNodeAddress = index;
+        for (int i = 0; i < ptNodeCount; ++i) {
+            final PtNode ptNode = ptNodeArray.mData.get(i);
+            if (index != ptNode.mCachedAddressAfterUpdate) {
                 throw new RuntimeException("Bug: write index is not the same as the cached address "
-                        + "of the group : " + index + " <> " + group.mCachedAddressAfterUpdate);
+                        + "of the node : " + index + " <> " + ptNode.mCachedAddressAfterUpdate);
             }
-            groupAddress += getGroupHeaderSize(group, formatOptions);
+            ptNodeAddress += getNodeHeaderSize(ptNode, formatOptions);
             // Sanity checks.
-            if (DBG && group.mFrequency > FormatSpec.MAX_TERMINAL_FREQUENCY) {
+            if (DBG && ptNode.mFrequency > FormatSpec.MAX_TERMINAL_FREQUENCY) {
                 throw new RuntimeException("A node has a frequency > "
                         + FormatSpec.MAX_TERMINAL_FREQUENCY
-                        + " : " + group.mFrequency);
+                        + " : " + ptNode.mFrequency);
             }
-            if (group.mFrequency >= 0) groupAddress += FormatSpec.GROUP_FREQUENCY_SIZE;
-            final int childrenOffset = null == group.mChildren
+            if (ptNode.mFrequency >= 0) ptNodeAddress += FormatSpec.PTNODE_FREQUENCY_SIZE;
+            final int childrenOffset = null == ptNode.mChildren
                     ? FormatSpec.NO_CHILDREN_ADDRESS
-                            : group.mChildren.mCachedAddressAfterUpdate - groupAddress;
+                            : ptNode.mChildren.mCachedAddressAfterUpdate - ptNodeAddress;
             buffer[index++] =
-                    makeCharGroupFlags(group, groupAddress, childrenOffset, formatOptions);
+                    makePtNodeFlags(ptNode, ptNodeAddress, childrenOffset, formatOptions);
 
             if (parentAddress == FormatSpec.NO_PARENT_ADDRESS) {
                 index = writeParentAddress(buffer, index, parentAddress, formatOptions);
             } else {
                 index = writeParentAddress(buffer, index, parentAddress
-                        + (nodeArray.mCachedAddressAfterUpdate - group.mCachedAddressAfterUpdate),
+                        + (ptNodeArray.mCachedAddressAfterUpdate
+                                - ptNode.mCachedAddressAfterUpdate),
                         formatOptions);
             }
 
-            index = CharEncoding.writeCharArray(group.mChars, buffer, index);
-            if (group.hasSeveralChars()) {
-                buffer[index++] = FormatSpec.GROUP_CHARACTERS_TERMINATOR;
+            index = CharEncoding.writeCharArray(ptNode.mChars, buffer, index);
+            if (ptNode.hasSeveralChars()) {
+                buffer[index++] = FormatSpec.PTNODE_CHARACTERS_TERMINATOR;
             }
-            if (group.mFrequency >= 0) {
-                buffer[index++] = (byte) group.mFrequency;
+            if (ptNode.mFrequency >= 0) {
+                buffer[index++] = (byte) ptNode.mFrequency;
             }
 
             final int shift;
@@ -793,23 +798,24 @@
                 shift = writeVariableAddress(buffer, index, childrenOffset);
             }
             index += shift;
-            groupAddress += shift;
+            ptNodeAddress += shift;
 
             // Write shortcuts
-            if (null != group.mShortcutTargets && !group.mShortcutTargets.isEmpty()) {
+            if (null != ptNode.mShortcutTargets && !ptNode.mShortcutTargets.isEmpty()) {
                 final int indexOfShortcutByteSize = index;
-                index += FormatSpec.GROUP_SHORTCUT_LIST_SIZE_SIZE;
-                groupAddress += FormatSpec.GROUP_SHORTCUT_LIST_SIZE_SIZE;
-                final Iterator<WeightedString> shortcutIterator = group.mShortcutTargets.iterator();
+                index += FormatSpec.PTNODE_SHORTCUT_LIST_SIZE_SIZE;
+                ptNodeAddress += FormatSpec.PTNODE_SHORTCUT_LIST_SIZE_SIZE;
+                final Iterator<WeightedString> shortcutIterator =
+                        ptNode.mShortcutTargets.iterator();
                 while (shortcutIterator.hasNext()) {
                     final WeightedString target = shortcutIterator.next();
-                    ++groupAddress;
+                    ++ptNodeAddress;
                     int shortcutFlags = makeShortcutFlags(shortcutIterator.hasNext(),
                             target.mFrequency);
                     buffer[index++] = (byte)shortcutFlags;
                     final int shortcutShift = CharEncoding.writeString(buffer, index, target.mWord);
                     index += shortcutShift;
-                    groupAddress += shortcutShift;
+                    ptNodeAddress += shortcutShift;
                 }
                 final int shortcutByteSize = index - indexOfShortcutByteSize;
                 if (shortcutByteSize > 0xFFFF) {
@@ -819,22 +825,22 @@
                 buffer[indexOfShortcutByteSize + 1] = (byte)(shortcutByteSize & 0xFF);
             }
             // Write bigrams
-            if (null != group.mBigrams) {
-                final Iterator<WeightedString> bigramIterator = group.mBigrams.iterator();
+            if (null != ptNode.mBigrams) {
+                final Iterator<WeightedString> bigramIterator = ptNode.mBigrams.iterator();
                 while (bigramIterator.hasNext()) {
                     final WeightedString bigram = bigramIterator.next();
-                    final CharGroup target =
+                    final PtNode target =
                             FusionDictionary.findWordInTree(dict.mRootNodeArray, bigram.mWord);
                     final int addressOfBigram = target.mCachedAddressAfterUpdate;
                     final int unigramFrequencyForThisWord = target.mFrequency;
-                    ++groupAddress;
-                    final int offset = addressOfBigram - groupAddress;
+                    ++ptNodeAddress;
+                    final int offset = addressOfBigram - ptNodeAddress;
                     int bigramFlags = makeBigramFlags(bigramIterator.hasNext(), offset,
                             bigram.mFrequency, unigramFrequencyForThisWord, bigram.mWord);
                     buffer[index++] = (byte)bigramFlags;
                     final int bigramShift = writeVariableAddress(buffer, index, Math.abs(offset));
                     index += bigramShift;
-                    groupAddress += bigramShift;
+                    ptNodeAddress += bigramShift;
                 }
             }
 
@@ -844,64 +850,64 @@
                     = FormatSpec.NO_FORWARD_LINK_ADDRESS;
             index += FormatSpec.FORWARD_LINK_ADDRESS_SIZE;
         }
-        if (index != nodeArray.mCachedAddressAfterUpdate + nodeArray.mCachedSize) {
+        if (index != ptNodeArray.mCachedAddressAfterUpdate + ptNodeArray.mCachedSize) {
             throw new RuntimeException(
-                    "Not the same size : written " + (index - nodeArray.mCachedAddressAfterUpdate)
-                     + " bytes from a node that should have " + nodeArray.mCachedSize + " bytes");
+                    "Not the same size : written " + (index - ptNodeArray.mCachedAddressAfterUpdate)
+                     + " bytes from a node that should have " + ptNodeArray.mCachedSize + " bytes");
         }
         return index;
     }
 
     /**
-     * Dumps a collection of useful statistics about a list of node arrays.
+     * Dumps a collection of useful statistics about a list of PtNode arrays.
      *
      * This prints purely informative stuff, like the total estimated file size, the
-     * number of node arrays, of character groups, the repartition of each address size, etc
+     * number of PtNode arrays, of PtNodes, the repartition of each address size, etc
      *
-     * @param nodeArrays the list of node arrays.
+     * @param ptNodeArrays the list of PtNode arrays.
      */
-    private static void showStatistics(ArrayList<PtNodeArray> nodeArrays) {
+    private static void showStatistics(ArrayList<PtNodeArray> ptNodeArrays) {
         int firstTerminalAddress = Integer.MAX_VALUE;
         int lastTerminalAddress = Integer.MIN_VALUE;
         int size = 0;
-        int charGroups = 0;
-        int maxGroups = 0;
+        int ptNodes = 0;
+        int maxNodes = 0;
         int maxRuns = 0;
-        for (final PtNodeArray nodeArray : nodeArrays) {
-            if (maxGroups < nodeArray.mData.size()) maxGroups = nodeArray.mData.size();
-            for (final CharGroup cg : nodeArray.mData) {
-                ++charGroups;
-                if (cg.mChars.length > maxRuns) maxRuns = cg.mChars.length;
-                if (cg.mFrequency >= 0) {
-                    if (nodeArray.mCachedAddressAfterUpdate < firstTerminalAddress)
-                        firstTerminalAddress = nodeArray.mCachedAddressAfterUpdate;
-                    if (nodeArray.mCachedAddressAfterUpdate > lastTerminalAddress)
-                        lastTerminalAddress = nodeArray.mCachedAddressAfterUpdate;
+        for (final PtNodeArray ptNodeArray : ptNodeArrays) {
+            if (maxNodes < ptNodeArray.mData.size()) maxNodes = ptNodeArray.mData.size();
+            for (final PtNode ptNode : ptNodeArray.mData) {
+                ++ptNodes;
+                if (ptNode.mChars.length > maxRuns) maxRuns = ptNode.mChars.length;
+                if (ptNode.mFrequency >= 0) {
+                    if (ptNodeArray.mCachedAddressAfterUpdate < firstTerminalAddress)
+                        firstTerminalAddress = ptNodeArray.mCachedAddressAfterUpdate;
+                    if (ptNodeArray.mCachedAddressAfterUpdate > lastTerminalAddress)
+                        lastTerminalAddress = ptNodeArray.mCachedAddressAfterUpdate;
                 }
             }
-            if (nodeArray.mCachedAddressAfterUpdate + nodeArray.mCachedSize > size) {
-                size = nodeArray.mCachedAddressAfterUpdate + nodeArray.mCachedSize;
+            if (ptNodeArray.mCachedAddressAfterUpdate + ptNodeArray.mCachedSize > size) {
+                size = ptNodeArray.mCachedAddressAfterUpdate + ptNodeArray.mCachedSize;
             }
         }
-        final int[] groupCounts = new int[maxGroups + 1];
+        final int[] ptNodeCounts = new int[maxNodes + 1];
         final int[] runCounts = new int[maxRuns + 1];
-        for (final PtNodeArray nodeArray : nodeArrays) {
-            ++groupCounts[nodeArray.mData.size()];
-            for (final CharGroup cg : nodeArray.mData) {
-                ++runCounts[cg.mChars.length];
+        for (final PtNodeArray ptNodeArray : ptNodeArrays) {
+            ++ptNodeCounts[ptNodeArray.mData.size()];
+            for (final PtNode ptNode : ptNodeArray.mData) {
+                ++runCounts[ptNode.mChars.length];
             }
         }
 
         MakedictLog.i("Statistics:\n"
                 + "  total file size " + size + "\n"
-                + "  " + nodeArrays.size() + " node arrays\n"
-                + "  " + charGroups + " groups (" + ((float)charGroups / nodeArrays.size())
-                        + " groups per node)\n"
+                + "  " + ptNodeArrays.size() + " node arrays\n"
+                + "  " + ptNodes + " PtNodes (" + ((float)ptNodes / ptNodeArrays.size())
+                        + " PtNodes per node)\n"
                 + "  first terminal at " + firstTerminalAddress + "\n"
                 + "  last terminal at " + lastTerminalAddress + "\n"
-                + "  Group stats : max = " + maxGroups);
-        for (int i = 0; i < groupCounts.length; ++i) {
-            MakedictLog.i("    " + i + " : " + groupCounts[i]);
+                + "  PtNode stats : max = " + maxNodes);
+        for (int i = 0; i < ptNodeCounts.length; ++i) {
+            MakedictLog.i("    " + i + " : " + ptNodeCounts[i]);
         }
         MakedictLog.i("  Character run stats : max = " + maxRuns);
         for (int i = 0; i < runCounts.length; ++i) {
@@ -922,7 +928,7 @@
 
         // Addresses are limited to 3 bytes, but since addresses can be relative to each node
         // array, the structure itself is not limited to 16MB. However, if it is over 16MB deciding
-        // the order of the node arrays becomes a quite complicated problem, because though the
+        // the order of the PtNode arrays becomes a quite complicated problem, because though the
         // dictionary itself does not have a size limit, each node array must still be within 16MB
         // of all its children and parents. As long as this is ensured, the dictionary file may
         // grow to any size.
@@ -980,8 +986,8 @@
 
         MakedictLog.i("Computing addresses...");
         computeAddresses(dict, flatNodes, formatOptions);
-        MakedictLog.i("Checking array...");
-        if (DBG) checkFlatNodeArrayList(flatNodes);
+        MakedictLog.i("Checking PtNode array...");
+        if (DBG) checkFlatPtNodeArrayList(flatNodes);
 
         // Create a buffer that matches the final dictionary size.
         final PtNodeArray lastNodeArray = flatNodes.get(flatNodes.size() - 1);
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
index 323afb4..245f003 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
@@ -22,7 +22,7 @@
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer;
 import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
-import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
+import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
 import com.android.inputmethod.latin.utils.ByteArrayDictBuffer;
 
@@ -44,17 +44,17 @@
     }
 
     private static final class Position {
-        public static final int NOT_READ_GROUPCOUNT = -1;
+        public static final int NOT_READ_PTNODE_COUNT = -1;
 
         public int mAddress;
-        public int mNumOfCharGroup;
+        public int mNumOfPtNode;
         public int mPosition;
         public int mLength;
 
         public Position(int address, int length) {
             mAddress = address;
             mLength = length;
-            mNumOfCharGroup = NOT_READ_GROUPCOUNT;
+            mNumOfPtNode = NOT_READ_PTNODE_COUNT;
         }
     }
 
@@ -79,45 +79,45 @@
             Position p = stack.peek();
 
             if (DBG) {
-                MakedictLog.d("read: address=" + p.mAddress + ", numOfCharGroup=" +
-                        p.mNumOfCharGroup + ", position=" + p.mPosition + ", length=" + p.mLength);
+                MakedictLog.d("read: address=" + p.mAddress + ", numOfPtNode=" +
+                        p.mNumOfPtNode + ", position=" + p.mPosition + ", length=" + p.mLength);
             }
 
             if (dictBuffer.position() != p.mAddress) dictBuffer.position(p.mAddress);
             if (index != p.mLength) index = p.mLength;
 
-            if (p.mNumOfCharGroup == Position.NOT_READ_GROUPCOUNT) {
-                p.mNumOfCharGroup = BinaryDictDecoderUtils.readCharGroupCount(dictBuffer);
-                p.mAddress += getGroupCountSize(p.mNumOfCharGroup);
+            if (p.mNumOfPtNode == Position.NOT_READ_PTNODE_COUNT) {
+                p.mNumOfPtNode = BinaryDictDecoderUtils.readPtNodeCount(dictBuffer);
+                p.mAddress += getPtNodeCountSize(p.mNumOfPtNode);
                 p.mPosition = 0;
             }
-            if (p.mNumOfCharGroup == 0) {
+            if (p.mNumOfPtNode == 0) {
                 stack.pop();
                 continue;
             }
-            CharGroupInfo info = dictDecoder.readPtNode(p.mAddress, formatOptions);
+            PtNodeInfo info = dictDecoder.readPtNode(p.mAddress, formatOptions);
             for (int i = 0; i < info.mCharacters.length; ++i) {
                 pushedChars[index++] = info.mCharacters[i];
             }
             p.mPosition++;
 
-            final boolean isMovedGroup = isMovedGroup(info.mFlags,
+            final boolean isMovedPtNode = isMovedPtNode(info.mFlags,
                     formatOptions);
-            final boolean isDeletedGroup = isDeletedGroup(info.mFlags,
+            final boolean isDeletedPtNode = isDeletedPtNode(info.mFlags,
                     formatOptions);
-            if (!isMovedGroup && !isDeletedGroup
-                    && info.mFrequency != FusionDictionary.CharGroup.NOT_A_TERMINAL) {// found word
+            if (!isMovedPtNode && !isDeletedPtNode
+                    && info.mFrequency != FusionDictionary.PtNode.NOT_A_TERMINAL) {// found word
                 words.put(info.mOriginalAddress, new String(pushedChars, 0, index));
                 frequencies.put(info.mOriginalAddress, info.mFrequency);
                 if (info.mBigrams != null) bigrams.put(info.mOriginalAddress, info.mBigrams);
             }
 
-            if (p.mPosition == p.mNumOfCharGroup) {
+            if (p.mPosition == p.mNumOfPtNode) {
                 if (formatOptions.mSupportsDynamicUpdate) {
                     final int forwardLinkAddress = dictBuffer.readUnsignedInt24();
                     if (forwardLinkAddress != FormatSpec.NO_FORWARD_LINK_ADDRESS) {
                         // The node array has a forward link.
-                        p.mNumOfCharGroup = Position.NOT_READ_GROUPCOUNT;
+                        p.mNumOfPtNode = Position.NOT_READ_PTNODE_COUNT;
                         p.mAddress = forwardLinkAddress;
                     } else {
                         stack.pop();
@@ -126,11 +126,11 @@
                     stack.pop();
                 }
             } else {
-                // The node array has more groups.
+                // The Ptnode array has more PtNodes.
                 p.mAddress = dictBuffer.position();
             }
 
-            if (!isMovedGroup && hasChildrenAddress(info.mChildrenAddress)) {
+            if (!isMovedPtNode && hasChildrenAddress(info.mChildrenAddress)) {
                 final Position childrenPos = new Position(info.mChildrenAddress, index);
                 stack.push(childrenPos);
             }
@@ -159,7 +159,7 @@
     }
 
     /**
-     * Gets the address of the last CharGroup of the exact matching word in the dictionary.
+     * Gets the address of the last PtNode of the exact matching word in the dictionary.
      * If no match is found, returns NOT_VALID_WORD.
      *
      * @param dictDecoder the dict decoder.
@@ -182,17 +182,17 @@
             if (wordPos >= wordLen) return FormatSpec.NOT_VALID_WORD;
 
             do {
-                final int charGroupCount = BinaryDictDecoderUtils.readCharGroupCount(dictBuffer);
-                boolean foundNextCharGroup = false;
-                for (int i = 0; i < charGroupCount; ++i) {
-                    final int charGroupPos = dictBuffer.position();
-                    final CharGroupInfo currentInfo = dictDecoder.readPtNode(charGroupPos,
+                final int ptNodeCount = BinaryDictDecoderUtils.readPtNodeCount(dictBuffer);
+                boolean foundNextPtNode = false;
+                for (int i = 0; i < ptNodeCount; ++i) {
+                    final int ptNodePos = dictBuffer.position();
+                    final PtNodeInfo currentInfo = dictDecoder.readPtNode(ptNodePos,
                             header.mFormatOptions);
-                    final boolean isMovedGroup = isMovedGroup(currentInfo.mFlags,
+                    final boolean isMovedNode = isMovedPtNode(currentInfo.mFlags,
                             header.mFormatOptions);
-                    final boolean isDeletedGroup = isDeletedGroup(currentInfo.mFlags,
+                    final boolean isDeletedNode = isDeletedPtNode(currentInfo.mFlags,
                             header.mFormatOptions);
-                    if (isMovedGroup) continue;
+                    if (isMovedNode) continue;
                     boolean same = true;
                     for (int p = 0, j = word.offsetByCodePoints(0, wordPos);
                             p < currentInfo.mCharacters.length;
@@ -205,30 +205,30 @@
                     }
 
                     if (same) {
-                        // found the group matches the word.
+                        // found the PtNode matches the word.
                         if (wordPos + currentInfo.mCharacters.length == wordLen) {
-                            if (currentInfo.mFrequency == CharGroup.NOT_A_TERMINAL
-                                    || isDeletedGroup) {
+                            if (currentInfo.mFrequency == PtNode.NOT_A_TERMINAL
+                                    || isDeletedNode) {
                                 return FormatSpec.NOT_VALID_WORD;
                             } else {
-                                return charGroupPos;
+                                return ptNodePos;
                             }
                         }
                         wordPos += currentInfo.mCharacters.length;
                         if (currentInfo.mChildrenAddress == FormatSpec.NO_CHILDREN_ADDRESS) {
                             return FormatSpec.NOT_VALID_WORD;
                         }
-                        foundNextCharGroup = true;
+                        foundNextPtNode = true;
                         dictBuffer.position(currentInfo.mChildrenAddress);
                         break;
                     }
                 }
 
-                // If we found the next char group, it is under the file pointer.
+                // If we found the next PtNode, it is under the file pointer.
                 // But if not, we are at the end of this node array so we expect to have
                 // a forward link address that we need to consult and possibly resume
                 // search on the next node array in the linked list.
-                if (foundNextCharGroup) break;
+                if (foundNextPtNode) break;
                 if (!header.mFormatOptions.mSupportsDynamicUpdate) {
                     return FormatSpec.NOT_VALID_WORD;
                 }
@@ -289,8 +289,7 @@
         return BinaryDictEncoderUtils.getByteSize(value);
     }
 
-    static void skipCharGroup(final DictBuffer dictBuffer,
-            final FormatOptions formatOptions) {
+    static void skipPtNode(final DictBuffer dictBuffer, final FormatOptions formatOptions) {
         final int flags = dictBuffer.readUnsignedByte();
         BinaryDictDecoderUtils.readParentAddress(dictBuffer, formatOptions);
         skipString(dictBuffer, (flags & FormatSpec.FLAG_HAS_MULTIPLE_CHARS) != 0);
@@ -299,27 +298,27 @@
         if ((flags & FormatSpec.FLAG_HAS_SHORTCUT_TARGETS) != 0) {
             final int shortcutsSize = dictBuffer.readUnsignedShort();
             dictBuffer.position(dictBuffer.position() + shortcutsSize
-                    - FormatSpec.GROUP_SHORTCUT_LIST_SIZE_SIZE);
+                    - FormatSpec.PTNODE_SHORTCUT_LIST_SIZE_SIZE);
         }
         if ((flags & FormatSpec.FLAG_HAS_BIGRAMS) != 0) {
             int bigramCount = 0;
-            while (bigramCount++ < FormatSpec.MAX_BIGRAMS_IN_A_GROUP) {
+            while (bigramCount++ < FormatSpec.MAX_BIGRAMS_IN_A_PTNODE) {
                 final int bigramFlags = dictBuffer.readUnsignedByte();
-                switch (bigramFlags & FormatSpec.MASK_ATTRIBUTE_ADDRESS_TYPE) {
-                    case FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE:
+                switch (bigramFlags & FormatSpec.MASK_BIGRAM_ATTR_ADDRESS_TYPE) {
+                    case FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE:
                         dictBuffer.readUnsignedByte();
                         break;
-                    case FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES:
+                    case FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_TWOBYTES:
                         dictBuffer.readUnsignedShort();
                         break;
-                    case FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES:
+                    case FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_THREEBYTES:
                         dictBuffer.readUnsignedInt24();
                         break;
                 }
-                if ((bigramFlags & FormatSpec.FLAG_ATTRIBUTE_HAS_NEXT) == 0) break;
+                if ((bigramFlags & FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT) == 0) break;
             }
-            if (bigramCount >= FormatSpec.MAX_BIGRAMS_IN_A_GROUP) {
-                throw new RuntimeException("Too many bigrams in a group.");
+            if (bigramCount >= FormatSpec.MAX_BIGRAMS_IN_A_PTNODE) {
+                throw new RuntimeException("Too many bigrams in a PtNode.");
             }
         }
     }
@@ -360,24 +359,24 @@
                 size += 3;
             }
         }
-        destination.write((byte)FormatSpec.GROUP_CHARACTERS_TERMINATOR);
-        size += FormatSpec.GROUP_TERMINATOR_SIZE;
+        destination.write((byte)FormatSpec.PTNODE_CHARACTERS_TERMINATOR);
+        size += FormatSpec.PTNODE_TERMINATOR_SIZE;
         return size;
     }
 
     /**
-     * Write a char group to an output stream from a CharGroupInfo.
-     * A char group is an in-memory representation of a node in the patricia trie.
-     * A char group info is a container for low-level information about how the
-     * char group is stored in the binary format.
+     * Write a PtNode to an output stream from a PtNodeInfo.
+     * A PtNode is an in-memory representation of a node in the patricia trie.
+     * A PtNode info is a container for low-level information about how the
+     * PtNode is stored in the binary format.
      *
      * @param destination the stream to write.
-     * @param info the char group info to be written.
+     * @param info the PtNode info to be written.
      * @return the size written, in bytes.
      */
-    private static int writeCharGroup(final OutputStream destination, final CharGroupInfo info)
+    private static int writePtNode(final OutputStream destination, final PtNodeInfo info)
             throws IOException {
-        int size = FormatSpec.GROUP_FLAGS_SIZE;
+        int size = FormatSpec.PTNODE_FLAGS_SIZE;
         destination.write((byte)info.mFlags);
         final int parentOffset = info.mParentAddress == FormatSpec.NO_PARENT_ADDRESS ?
                 FormatSpec.NO_PARENT_ADDRESS : info.mParentAddress - info.mOriginalAddress;
@@ -392,7 +391,7 @@
             }
         }
         if (info.mCharacters.length > 1) {
-            destination.write((byte)FormatSpec.GROUP_CHARACTERS_TERMINATOR);
+            destination.write((byte)FormatSpec.PTNODE_CHARACTERS_TERMINATOR);
             size++;
         }
 
@@ -402,7 +401,7 @@
         }
 
         if (DBG) {
-            MakedictLog.d("writeCharGroup origin=" + info.mOriginalAddress + ", size=" + size
+            MakedictLog.d("writePtNode origin=" + info.mOriginalAddress + ", size=" + size
                     + ", child=" + info.mChildrenAddress + ", characters ="
                     + new String(info.mCharacters, 0, info.mCharacters.length));
         }
@@ -434,23 +433,23 @@
 
                 final int bigramFrequency = info.mBigrams.get(i).mFrequency;
                 int bigramFlags = (i < info.mBigrams.size() - 1)
-                        ? FormatSpec.FLAG_ATTRIBUTE_HAS_NEXT : 0;
+                        ? FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT : 0;
                 size++;
                 final int bigramOffset = info.mBigrams.get(i).mAddress - (info.mOriginalAddress
                         + size);
-                bigramFlags |= (bigramOffset < 0) ? FormatSpec.FLAG_ATTRIBUTE_OFFSET_NEGATIVE : 0;
+                bigramFlags |= (bigramOffset < 0) ? FormatSpec.FLAG_BIGRAM_ATTR_OFFSET_NEGATIVE : 0;
                 switch (BinaryDictEncoderUtils.getByteSize(bigramOffset)) {
                 case 1:
-                    bigramFlags |= FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE;
+                    bigramFlags |= FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE;
                     break;
                 case 2:
-                    bigramFlags |= FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES;
+                    bigramFlags |= FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_TWOBYTES;
                     break;
                 case 3:
-                    bigramFlags |= FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES;
+                    bigramFlags |= FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_THREEBYTES;
                     break;
                 }
-                bigramFlags |= bigramFrequency & FormatSpec.FLAG_ATTRIBUTE_FREQUENCY;
+                bigramFlags |= bigramFrequency & FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY;
                 destination.write((byte)bigramFlags);
                 size += writeVariableAddress(destination, Math.abs(bigramOffset));
             }
@@ -459,21 +458,21 @@
     }
 
     /**
-     * Compute the size of the char group.
+     * Compute the size of the PtNode.
      */
-    static int computeGroupSize(final CharGroupInfo info, final FormatOptions formatOptions) {
-        int size = FormatSpec.GROUP_FLAGS_SIZE + FormatSpec.PARENT_ADDRESS_SIZE
-                + BinaryDictEncoderUtils.getGroupCharactersSize(info.mCharacters)
+    static int computePtNodeSize(final PtNodeInfo info, final FormatOptions formatOptions) {
+        int size = FormatSpec.PTNODE_FLAGS_SIZE + FormatSpec.PARENT_ADDRESS_SIZE
+                + BinaryDictEncoderUtils.getPtNodeCharactersSize(info.mCharacters)
                 + getChildrenAddressSize(info.mFlags, formatOptions);
         if ((info.mFlags & FormatSpec.FLAG_IS_TERMINAL) != 0) {
-            size += FormatSpec.GROUP_FREQUENCY_SIZE;
+            size += FormatSpec.PTNODE_FREQUENCY_SIZE;
         }
         if (info.mShortcutTargets != null && !info.mShortcutTargets.isEmpty()) {
             size += BinaryDictEncoderUtils.getShortcutListSize(info.mShortcutTargets);
         }
         if (info.mBigrams != null) {
             for (final PendingAttribute attr : info.mBigrams) {
-                size += FormatSpec.GROUP_FLAGS_SIZE;
+                size += FormatSpec.PTNODE_FLAGS_SIZE;
                 size += BinaryDictEncoderUtils.getByteSize(attr.mAddress);
             }
         }
@@ -484,14 +483,14 @@
      * Write a node array to the stream.
      *
      * @param destination the stream to write.
-     * @param infos an array of CharGroupInfo to be written.
+     * @param infos an array of PtNodeInfo to be written.
      * @return the size written, in bytes.
      * @throws IOException
      */
-    static int writeNodes(final OutputStream destination, final CharGroupInfo[] infos)
+    static int writeNodes(final OutputStream destination, final PtNodeInfo[] infos)
             throws IOException {
-        int size = getGroupCountSize(infos.length);
-        switch (getGroupCountSize(infos.length)) {
+        int size = getPtNodeCountSize(infos.length);
+        switch (getPtNodeCountSize(infos.length)) {
             case 1:
                 destination.write((byte)infos.length);
                 break;
@@ -500,9 +499,9 @@
                 destination.write((byte)(infos.length & 0xFF));
                 break;
             default:
-                throw new RuntimeException("Invalid group count size.");
+                throw new RuntimeException("Invalid node count size.");
         }
-        for (final CharGroupInfo info : infos) size += writeCharGroup(destination, info);
+        for (final PtNodeInfo info : infos) size += writePtNode(destination, info);
         writeSInt24ToStream(destination, FormatSpec.NO_FORWARD_LINK_ADDRESS);
         return size + FormatSpec.FORWARD_LINK_ADDRESS_SIZE;
     }
@@ -560,11 +559,11 @@
     }
 
     /**
-     * Helper method to check whether the group is moved.
+     * Helper method to check whether the node is moved.
      */
-    public static boolean isMovedGroup(final int flags, final FormatOptions options) {
+    public static boolean isMovedPtNode(final int flags, final FormatOptions options) {
         return options.mSupportsDynamicUpdate
-                && ((flags & FormatSpec.MASK_GROUP_ADDRESS_TYPE) == FormatSpec.FLAG_IS_MOVED);
+                && ((flags & FormatSpec.MASK_CHILDREN_ADDRESS_TYPE) == FormatSpec.FLAG_IS_MOVED);
     }
 
     /**
@@ -576,26 +575,26 @@
     }
 
     /**
-     * Helper method to check whether the group is deleted.
+     * Helper method to check whether the node is deleted.
      */
-    public static boolean isDeletedGroup(final int flags, final FormatOptions formatOptions) {
+    public static boolean isDeletedPtNode(final int flags, final FormatOptions formatOptions) {
         return formatOptions.mSupportsDynamicUpdate
-                && ((flags & FormatSpec.MASK_GROUP_ADDRESS_TYPE) == FormatSpec.FLAG_IS_DELETED);
+                && ((flags & FormatSpec.MASK_CHILDREN_ADDRESS_TYPE) == FormatSpec.FLAG_IS_DELETED);
     }
 
     /**
-     * Compute the binary size of the group count
-     * @param count the group count
-     * @return the size of the group count, either 1 or 2 bytes.
+     * Compute the binary size of the node count
+     * @param count the node count
+     * @return the size of the node count, either 1 or 2 bytes.
      */
-    public static int getGroupCountSize(final int count) {
-        if (FormatSpec.MAX_CHARGROUPS_FOR_ONE_BYTE_CHARGROUP_COUNT >= count) {
+    public static int getPtNodeCountSize(final int count) {
+        if (FormatSpec.MAX_PTNODES_FOR_ONE_BYTE_PTNODE_COUNT >= count) {
             return 1;
-        } else if (FormatSpec.MAX_CHARGROUPS_IN_A_PT_NODE_ARRAY >= count) {
+        } else if (FormatSpec.MAX_PTNODES_IN_A_PT_NODE_ARRAY >= count) {
             return 2;
         } else {
             throw new RuntimeException("Can't have more than "
-                    + FormatSpec.MAX_CHARGROUPS_IN_A_PT_NODE_ARRAY + " groups in a node (found "
+                    + FormatSpec.MAX_PTNODES_IN_A_PT_NODE_ARRAY + " PtNode in a PtNodeArray (found "
                     + count + ")");
         }
     }
@@ -603,14 +602,14 @@
     static int getChildrenAddressSize(final int optionFlags,
             final FormatOptions formatOptions) {
         if (formatOptions.mSupportsDynamicUpdate) return FormatSpec.SIGNED_CHILDREN_ADDRESS_SIZE;
-        switch (optionFlags & FormatSpec.MASK_GROUP_ADDRESS_TYPE) {
-            case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_ONEBYTE:
+        switch (optionFlags & FormatSpec.MASK_CHILDREN_ADDRESS_TYPE) {
+            case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE:
                 return 1;
-            case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_TWOBYTES:
+            case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES:
                 return 2;
-            case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_THREEBYTES:
+            case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES:
                 return 3;
-            case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_NOADDRESS:
+            case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS:
             default:
                 return 0;
         }
diff --git a/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java
index 13a42fa..5be5069 100644
--- a/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java
@@ -40,9 +40,9 @@
      * Reads PtNode from nodeAddress.
      * @param ptNodePos the position of PtNode.
      * @param formatOptions the format options.
-     * @return CharGroupInfo.
+     * @return PtNodeInfo.
      */
-    public CharGroupInfo readPtNode(final int ptNodePos, final FormatOptions formatOptions);
+    public PtNodeInfo readPtNode(final int ptNodePos, final FormatOptions formatOptions);
 
     /**
      * Reads a buffer and returns the memory representation of the dictionary.
diff --git a/java/src/com/android/inputmethod/latin/makedict/DynamicBinaryDictIOUtils.java b/java/src/com/android/inputmethod/latin/makedict/DynamicBinaryDictIOUtils.java
index f976c81..77dba88 100644
--- a/java/src/com/android/inputmethod/latin/makedict/DynamicBinaryDictIOUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/DynamicBinaryDictIOUtils.java
@@ -43,7 +43,7 @@
     }
 
     private static int markAsDeleted(final int flags) {
-        return (flags & (~FormatSpec.MASK_GROUP_ADDRESS_TYPE)) | FormatSpec.FLAG_IS_DELETED;
+        return (flags & (~FormatSpec.MASK_CHILDREN_ADDRESS_TYPE)) | FormatSpec.FLAG_IS_DELETED;
     }
 
     /**
@@ -70,56 +70,56 @@
     }
 
     /**
-     * Update a parent address in a CharGroup that is referred to by groupOriginAddress.
+     * Update a parent address in a PtNode that is referred to by ptNodeOriginAddress.
      *
      * @param dictBuffer the DictBuffer to write.
-     * @param groupOriginAddress the address of the group.
+     * @param ptNodeOriginAddress the address of the PtNode.
      * @param newParentAddress the absolute address of the parent.
      * @param formatOptions file format options.
      */
     public static void updateParentAddress(final DictBuffer dictBuffer,
-            final int groupOriginAddress, final int newParentAddress,
+            final int ptNodeOriginAddress, final int newParentAddress,
             final FormatOptions formatOptions) {
         final int originalPosition = dictBuffer.position();
-        dictBuffer.position(groupOriginAddress);
+        dictBuffer.position(ptNodeOriginAddress);
         if (!formatOptions.mSupportsDynamicUpdate) {
             throw new RuntimeException("this file format does not support parent addresses");
         }
         final int flags = dictBuffer.readUnsignedByte();
-        if (BinaryDictIOUtils.isMovedGroup(flags, formatOptions)) {
-            // If the group is moved, the parent address is stored in the destination group.
-            // We are guaranteed to process the destination group later, so there is no need to
+        if (BinaryDictIOUtils.isMovedPtNode(flags, formatOptions)) {
+            // If the node is moved, the parent address is stored in the destination node.
+            // We are guaranteed to process the destination node later, so there is no need to
             // update anything here.
             dictBuffer.position(originalPosition);
             return;
         }
         if (DBG) {
-            MakedictLog.d("update parent address flags=" + flags + ", " + groupOriginAddress);
+            MakedictLog.d("update parent address flags=" + flags + ", " + ptNodeOriginAddress);
         }
-        final int parentOffset = newParentAddress - groupOriginAddress;
+        final int parentOffset = newParentAddress - ptNodeOriginAddress;
         BinaryDictIOUtils.writeSInt24ToBuffer(dictBuffer, parentOffset);
         dictBuffer.position(originalPosition);
     }
 
     /**
-     * Update parent addresses in a node array stored at nodeOriginAddress.
+     * Update parent addresses in a node array stored at ptNodeOriginAddress.
      *
      * @param dictBuffer the DictBuffer to be modified.
-     * @param nodeOriginAddress the address of the node array to update.
+     * @param ptNodeOriginAddress the address of the node array to update.
      * @param newParentAddress the address to be written.
      * @param formatOptions file format options.
      */
     public static void updateParentAddresses(final DictBuffer dictBuffer,
-            final int nodeOriginAddress, final int newParentAddress,
+            final int ptNodeOriginAddress, final int newParentAddress,
             final FormatOptions formatOptions) {
         final int originalPosition = dictBuffer.position();
-        dictBuffer.position(nodeOriginAddress);
+        dictBuffer.position(ptNodeOriginAddress);
         do {
-            final int count = BinaryDictDecoderUtils.readCharGroupCount(dictBuffer);
+            final int count = BinaryDictDecoderUtils.readPtNodeCount(dictBuffer);
             for (int i = 0; i < count; ++i) {
                 updateParentAddress(dictBuffer, dictBuffer.position(), newParentAddress,
                         formatOptions);
-                BinaryDictIOUtils.skipCharGroup(dictBuffer, formatOptions);
+                BinaryDictIOUtils.skipPtNode(dictBuffer, formatOptions);
             }
             final int forwardLinkAddress = dictBuffer.readUnsignedInt24();
             dictBuffer.position(forwardLinkAddress);
@@ -129,18 +129,18 @@
     }
 
     /**
-     * Update a children address in a CharGroup that is addressed by groupOriginAddress.
+     * Update a children address in a PtNode that is addressed by ptNodeOriginAddress.
      *
      * @param dictBuffer the DictBuffer to write.
-     * @param groupOriginAddress the address of the group.
+     * @param ptNodeOriginAddress the address of the PtNode.
      * @param newChildrenAddress the absolute address of the child.
      * @param formatOptions file format options.
      */
     public static void updateChildrenAddress(final DictBuffer dictBuffer,
-            final int groupOriginAddress, final int newChildrenAddress,
+            final int ptNodeOriginAddress, final int newChildrenAddress,
             final FormatOptions formatOptions) {
         final int originalPosition = dictBuffer.position();
-        dictBuffer.position(groupOriginAddress);
+        dictBuffer.position(ptNodeOriginAddress);
         final int flags = dictBuffer.readUnsignedByte();
         final int parentAddress = BinaryDictDecoderUtils.readParentAddress(dictBuffer,
                 formatOptions);
@@ -153,21 +153,21 @@
     }
 
     /**
-     * Helper method to move a char group to the tail of the file.
+     * Helper method to move a PtNode to the tail of the file.
      */
-    private static int moveCharGroup(final OutputStream destination,
-            final DictBuffer dictBuffer, final CharGroupInfo info,
-            final int nodeArrayOriginAddress, final int oldGroupAddress,
+    private static int movePtNode(final OutputStream destination,
+            final DictBuffer dictBuffer, final PtNodeInfo info,
+            final int nodeArrayOriginAddress, final int oldNodeAddress,
             final FormatOptions formatOptions) throws IOException {
-        updateParentAddress(dictBuffer, oldGroupAddress, dictBuffer.limit() + 1, formatOptions);
-        dictBuffer.position(oldGroupAddress);
+        updateParentAddress(dictBuffer, oldNodeAddress, dictBuffer.limit() + 1, formatOptions);
+        dictBuffer.position(oldNodeAddress);
         final int currentFlags = dictBuffer.readUnsignedByte();
-        dictBuffer.position(oldGroupAddress);
+        dictBuffer.position(oldNodeAddress);
         dictBuffer.put((byte)(FormatSpec.FLAG_IS_MOVED | (currentFlags
                 & (~FormatSpec.MASK_MOVE_AND_DELETE_FLAG))));
-        int size = FormatSpec.GROUP_FLAGS_SIZE;
+        int size = FormatSpec.PTNODE_FLAGS_SIZE;
         updateForwardLink(dictBuffer, nodeArrayOriginAddress, dictBuffer.limit(), formatOptions);
-        size += BinaryDictIOUtils.writeNodes(destination, new CharGroupInfo[] { info });
+        size += BinaryDictIOUtils.writeNodes(destination, new PtNodeInfo[] { info });
         return size;
     }
 
@@ -178,9 +178,9 @@
         dictBuffer.position(nodeArrayOriginAddress);
         int jumpCount = 0;
         while (jumpCount++ < MAX_JUMPS) {
-            final int count = BinaryDictDecoderUtils.readCharGroupCount(dictBuffer);
+            final int count = BinaryDictDecoderUtils.readPtNodeCount(dictBuffer);
             for (int i = 0; i < count; ++i) {
-                BinaryDictIOUtils.skipCharGroup(dictBuffer, formatOptions);
+                BinaryDictIOUtils.skipPtNode(dictBuffer, formatOptions);
             }
             final int forwardLinkAddress = dictBuffer.readUnsignedInt24();
             if (forwardLinkAddress == FormatSpec.NO_FORWARD_LINK_ADDRESS) {
@@ -196,43 +196,43 @@
     }
 
     /**
-     * Move a group that is referred to by oldGroupOrigin to the tail of the file, and set the
-     * children address to the byte after the group
+     * Move a PtNode that is referred to by oldPtNodeOrigin to the tail of the file, and set the
+     * children address to the byte after the PtNode.
      *
      * @param fileEndAddress the address of the tail of the file.
-     * @param codePoints the characters to put inside the group.
+     * @param codePoints the characters to put inside the PtNode.
      * @param length how many code points to read from codePoints.
-     * @param flags the flags for this group.
+     * @param flags the flags for this PtNode.
      * @param frequency the frequency of this terminal.
-     * @param parentAddress the address of the parent group of this group.
-     * @param shortcutTargets the shortcut targets for this group.
-     * @param bigrams the bigrams for this group.
+     * @param parentAddress the address of the parent PtNode of this PtNode.
+     * @param shortcutTargets the shortcut targets for this PtNode.
+     * @param bigrams the bigrams for this PtNode.
      * @param destination the stream representing the tail of the file.
      * @param dictBuffer the DictBuffer representing the (constant-size) body of the file.
-     * @param oldNodeArrayOrigin the origin of the old node array this group was a part of.
-     * @param oldGroupOrigin the old origin where this group used to be stored.
+     * @param oldPtNodeArrayOrigin the origin of the old PtNode array this PtNode was a part of.
+     * @param oldPtNodeOrigin the old origin where this PtNode used to be stored.
      * @param formatOptions format options for this dictionary.
      * @return the size written, in bytes.
      * @throws IOException if the file can't be accessed
      */
-    private static int moveGroup(final int fileEndAddress, final int[] codePoints,
+    private static int movePtNode(final int fileEndAddress, final int[] codePoints,
             final int length, final int flags, final int frequency, final int parentAddress,
             final ArrayList<WeightedString> shortcutTargets,
             final ArrayList<PendingAttribute> bigrams, final OutputStream destination,
-            final DictBuffer dictBuffer, final int oldNodeArrayOrigin,
-            final int oldGroupOrigin, final FormatOptions formatOptions) throws IOException {
+            final DictBuffer dictBuffer, final int oldPtNodeArrayOrigin,
+            final int oldPtNodeOrigin, final FormatOptions formatOptions) throws IOException {
         int size = 0;
-        final int newGroupOrigin = fileEndAddress + 1;
+        final int newPtNodeOrigin = fileEndAddress + 1;
         final int[] writtenCharacters = Arrays.copyOfRange(codePoints, 0, length);
-        final CharGroupInfo tmpInfo = new CharGroupInfo(newGroupOrigin, -1 /* endAddress */,
+        final PtNodeInfo tmpInfo = new PtNodeInfo(newPtNodeOrigin, -1 /* endAddress */,
                 flags, writtenCharacters, frequency, parentAddress, FormatSpec.NO_CHILDREN_ADDRESS,
                 shortcutTargets, bigrams);
-        size = BinaryDictIOUtils.computeGroupSize(tmpInfo, formatOptions);
-        final CharGroupInfo newInfo = new CharGroupInfo(newGroupOrigin, newGroupOrigin + size,
+        size = BinaryDictIOUtils.computePtNodeSize(tmpInfo, formatOptions);
+        final PtNodeInfo newInfo = new PtNodeInfo(newPtNodeOrigin, newPtNodeOrigin + size,
                 flags, writtenCharacters, frequency, parentAddress,
                 fileEndAddress + 1 + size + FormatSpec.FORWARD_LINK_ADDRESS_SIZE, shortcutTargets,
                 bigrams);
-        moveCharGroup(destination, dictBuffer, newInfo, oldNodeArrayOrigin, oldGroupOrigin,
+        movePtNode(destination, dictBuffer, newInfo, oldPtNodeArrayOrigin, oldPtNodeOrigin,
                 formatOptions);
         return 1 + size + FormatSpec.FORWARD_LINK_ADDRESS_SIZE;
     }
@@ -288,16 +288,16 @@
             if (wordPos >= wordLen) break;
             nodeOriginAddress = dictBuffer.position();
             int nodeParentAddress = -1;
-            final int charGroupCount = BinaryDictDecoderUtils.readCharGroupCount(dictBuffer);
-            boolean foundNextGroup = false;
+            final int ptNodeCount = BinaryDictDecoderUtils.readPtNodeCount(dictBuffer);
+            boolean foundNextNode = false;
 
-            for (int i = 0; i < charGroupCount; ++i) {
+            for (int i = 0; i < ptNodeCount; ++i) {
                 address = dictBuffer.position();
-                final CharGroupInfo currentInfo = dictDecoder.readPtNode(address,
+                final PtNodeInfo currentInfo = dictDecoder.readPtNode(address,
                         fileHeader.mFormatOptions);
-                final boolean isMovedGroup = BinaryDictIOUtils.isMovedGroup(currentInfo.mFlags,
+                final boolean isMovedNode = BinaryDictIOUtils.isMovedPtNode(currentInfo.mFlags,
                         fileHeader.mFormatOptions);
-                if (isMovedGroup) continue;
+                if (isMovedNode) continue;
                 nodeParentAddress = (currentInfo.mParentAddress == FormatSpec.NO_PARENT_ADDRESS)
                         ? FormatSpec.NO_PARENT_ADDRESS : currentInfo.mParentAddress + address;
                 boolean matched = true;
@@ -314,10 +314,10 @@
                          *  abc - d - ef
                          */
                         final int newNodeAddress = dictBuffer.limit();
-                        final int flags = BinaryDictEncoderUtils.makeCharGroupFlags(p > 1,
+                        final int flags = BinaryDictEncoderUtils.makePtNodeFlags(p > 1,
                                 isTerminal, 0, hasShortcuts, hasBigrams, false /* isNotAWord */,
                                 false /* isBlackListEntry */, fileHeader.mFormatOptions);
-                        int written = moveGroup(newNodeAddress, currentInfo.mCharacters, p, flags,
+                        int written = movePtNode(newNodeAddress, currentInfo.mCharacters, p, flags,
                                 frequency, nodeParentAddress, shortcuts, bigrams, destination,
                                 dictBuffer, nodeOriginAddress, address, fileHeader.mFormatOptions);
 
@@ -327,12 +327,12 @@
                             updateParentAddresses(dictBuffer, currentInfo.mChildrenAddress,
                                     newNodeAddress + written + 1, fileHeader.mFormatOptions);
                         }
-                        final CharGroupInfo newInfo2 = new CharGroupInfo(
+                        final PtNodeInfo newInfo2 = new PtNodeInfo(
                                 newNodeAddress + written + 1, -1 /* endAddress */,
                                 currentInfo.mFlags, characters2, currentInfo.mFrequency,
                                 newNodeAddress + 1, currentInfo.mChildrenAddress,
                                 currentInfo.mShortcutTargets, currentInfo.mBigrams);
-                        BinaryDictIOUtils.writeNodes(destination, new CharGroupInfo[] { newInfo2 });
+                        BinaryDictIOUtils.writeNodes(destination, new PtNodeInfo[] { newInfo2 });
                         return;
                     } else if (codePoints[wordPos + p] != currentInfo.mCharacters[p]) {
                         if (p > 0) {
@@ -353,12 +353,12 @@
                             final int childrenAddress = currentInfo.mChildrenAddress;
 
                             // move prefix
-                            final int prefixFlags = BinaryDictEncoderUtils.makeCharGroupFlags(p > 1,
+                            final int prefixFlags = BinaryDictEncoderUtils.makePtNodeFlags(p > 1,
                                     false /* isTerminal */, 0 /* childrenAddressSize*/,
                                     false /* hasShortcut */, false /* hasBigrams */,
                                     false /* isNotAWord */, false /* isBlackListEntry */,
                                     fileHeader.mFormatOptions);
-                            int written = moveGroup(newNodeAddress, currentInfo.mCharacters, p,
+                            int written = movePtNode(newNodeAddress, currentInfo.mCharacters, p,
                                     prefixFlags, -1 /* frequency */, nodeParentAddress, null, null,
                                     destination, dictBuffer, nodeOriginAddress, address,
                                     fileHeader.mFormatOptions);
@@ -369,7 +369,7 @@
                                 updateParentAddresses(dictBuffer, currentInfo.mChildrenAddress,
                                         newNodeAddress + written + 1, fileHeader.mFormatOptions);
                             }
-                            final int suffixFlags = BinaryDictEncoderUtils.makeCharGroupFlags(
+                            final int suffixFlags = BinaryDictEncoderUtils.makePtNodeFlags(
                                     suffixCharacters.length > 1,
                                     (currentInfo.mFlags & FormatSpec.FLAG_IS_TERMINAL) != 0,
                                     0 /* childrenAddressSize */,
@@ -377,26 +377,26 @@
                                             != 0,
                                     (currentInfo.mFlags & FormatSpec.FLAG_HAS_BIGRAMS) != 0,
                                     isNotAWord, isBlackListEntry, fileHeader.mFormatOptions);
-                            final CharGroupInfo suffixInfo = new CharGroupInfo(
+                            final PtNodeInfo suffixInfo = new PtNodeInfo(
                                     newNodeAddress + written + 1, -1 /* endAddress */, suffixFlags,
                                     suffixCharacters, currentInfo.mFrequency, newNodeAddress + 1,
                                     currentInfo.mChildrenAddress, currentInfo.mShortcutTargets,
                                     currentInfo.mBigrams);
-                            written += BinaryDictIOUtils.computeGroupSize(suffixInfo,
+                            written += BinaryDictIOUtils.computePtNodeSize(suffixInfo,
                                     fileHeader.mFormatOptions) + 1;
 
                             final int[] newCharacters = Arrays.copyOfRange(codePoints, wordPos + p,
                                     codePoints.length);
-                            final int flags = BinaryDictEncoderUtils.makeCharGroupFlags(
+                            final int flags = BinaryDictEncoderUtils.makePtNodeFlags(
                                     newCharacters.length > 1, isTerminal,
                                     0 /* childrenAddressSize */, hasShortcuts, hasBigrams,
                                     isNotAWord, isBlackListEntry, fileHeader.mFormatOptions);
-                            final CharGroupInfo newInfo = new CharGroupInfo(
+                            final PtNodeInfo newInfo = new PtNodeInfo(
                                     newNodeAddress + written, -1 /* endAddress */, flags,
                                     newCharacters, frequency, newNodeAddress + 1,
                                     FormatSpec.NO_CHILDREN_ADDRESS, shortcuts, bigrams);
                             BinaryDictIOUtils.writeNodes(destination,
-                                    new CharGroupInfo[] { suffixInfo, newInfo });
+                                    new PtNodeInfo[] { suffixInfo, newInfo });
                             return;
                         }
                         matched = false;
@@ -407,17 +407,17 @@
                 if (matched) {
                     if (wordPos + currentInfo.mCharacters.length == wordLen) {
                         // the word exists in the dictionary.
-                        // only update group.
+                        // only update the PtNode.
                         final int newNodeAddress = dictBuffer.limit();
                         final boolean hasMultipleChars = currentInfo.mCharacters.length > 1;
-                        final int flags = BinaryDictEncoderUtils.makeCharGroupFlags(hasMultipleChars,
+                        final int flags = BinaryDictEncoderUtils.makePtNodeFlags(hasMultipleChars,
                                 isTerminal, 0 /* childrenAddressSize */, hasShortcuts, hasBigrams,
                                 isNotAWord, isBlackListEntry, fileHeader.mFormatOptions);
-                        final CharGroupInfo newInfo = new CharGroupInfo(newNodeAddress + 1,
+                        final PtNodeInfo newInfo = new PtNodeInfo(newNodeAddress + 1,
                                 -1 /* endAddress */, flags, currentInfo.mCharacters, frequency,
                                 nodeParentAddress, currentInfo.mChildrenAddress, shortcuts,
                                 bigrams);
-                        moveCharGroup(destination, dictBuffer, newInfo, nodeOriginAddress, address,
+                        movePtNode(destination, dictBuffer, newInfo, nodeOriginAddress, address,
                                 fileHeader.mFormatOptions);
                         return;
                     }
@@ -425,7 +425,7 @@
                     if (currentInfo.mChildrenAddress == FormatSpec.NO_CHILDREN_ADDRESS) {
                         /*
                          * found the prefix of the word.
-                         * make new node and link to the node from this group.
+                         * make new PtNode and link to the PtNode from this PtNode.
                          *
                          * before
                          * ab - cd
@@ -435,28 +435,28 @@
                          * after
                          * ab - cd - e
                          */
-                        final int newNodeAddress = dictBuffer.limit();
-                        updateChildrenAddress(dictBuffer, address, newNodeAddress,
+                        final int newNodeArrayAddress = dictBuffer.limit();
+                        updateChildrenAddress(dictBuffer, address, newNodeArrayAddress,
                                 fileHeader.mFormatOptions);
-                        final int newGroupAddress = newNodeAddress + 1;
+                        final int newNodeAddress = newNodeArrayAddress + 1;
                         final boolean hasMultipleChars = (wordLen - wordPos) > 1;
-                        final int flags = BinaryDictEncoderUtils.makeCharGroupFlags(hasMultipleChars,
+                        final int flags = BinaryDictEncoderUtils.makePtNodeFlags(hasMultipleChars,
                                 isTerminal, 0 /* childrenAddressSize */, hasShortcuts, hasBigrams,
                                 isNotAWord, isBlackListEntry, fileHeader.mFormatOptions);
                         final int[] characters = Arrays.copyOfRange(codePoints, wordPos, wordLen);
-                        final CharGroupInfo newInfo = new CharGroupInfo(newGroupAddress, -1, flags,
+                        final PtNodeInfo newInfo = new PtNodeInfo(newNodeAddress, -1, flags,
                                 characters, frequency, address, FormatSpec.NO_CHILDREN_ADDRESS,
                                 shortcuts, bigrams);
-                        BinaryDictIOUtils.writeNodes(destination, new CharGroupInfo[] { newInfo });
+                        BinaryDictIOUtils.writeNodes(destination, new PtNodeInfo[] { newInfo });
                         return;
                     }
                     dictBuffer.position(currentInfo.mChildrenAddress);
-                    foundNextGroup = true;
+                    foundNextNode = true;
                     break;
                 }
             }
 
-            if (foundNextGroup) continue;
+            if (foundNextNode) continue;
 
             // reached the end of the array.
             final int linkAddressPosition = dictBuffer.position();
@@ -485,13 +485,13 @@
                 BinaryDictIOUtils.writeSInt24ToBuffer(dictBuffer, newNodeAddress);
 
                 final int[] characters = Arrays.copyOfRange(codePoints, wordPos, wordLen);
-                final int flags = BinaryDictEncoderUtils.makeCharGroupFlags(characters.length > 1,
+                final int flags = BinaryDictEncoderUtils.makePtNodeFlags(characters.length > 1,
                         isTerminal, 0 /* childrenAddressSize */, hasShortcuts, hasBigrams,
                         isNotAWord, isBlackListEntry, fileHeader.mFormatOptions);
-                final CharGroupInfo newInfo = new CharGroupInfo(newNodeAddress + 1,
+                final PtNodeInfo newInfo = new PtNodeInfo(newNodeAddress + 1,
                         -1 /* endAddress */, flags, characters, frequency, nodeParentAddress,
                         FormatSpec.NO_CHILDREN_ADDRESS, shortcuts, bigrams);
-                BinaryDictIOUtils.writeNodes(destination, new CharGroupInfo[]{ newInfo });
+                BinaryDictIOUtils.writeNodes(destination, new PtNodeInfo[]{ newInfo });
                 return;
             } else {
                 depth--;
diff --git a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
index 5e33121..b8ef576 100644
--- a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
+++ b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
@@ -62,19 +62,19 @@
     /*
      * Node array (FusionDictionary.PtNodeArray) layout is as follows:
      *
-     * g |
-     * r | the number of groups, 1 or 2 bytes.
-     * o | 1 byte = bbbbbbbb match
-     * u |   case 1xxxxxxx => xxxxxxx << 8 + next byte
-     * p |   otherwise => bbbbbbbb
-     * c |
-     * ount
+     * n |
+     * o | the number of PtNodes, 1 or 2 bytes.
+     * d | 1 byte = bbbbbbbb match
+     * e |   case 1xxxxxxx => xxxxxxx << 8 + next byte
+     * c |   otherwise => bbbbbbbb
+     * o |
+     * unt
      *
-     * g |
-     * r | sequence of groups,
-     * o | the layout of each group is described below.
-     * u |
-     * ps
+     * n |
+     * o | sequence of PtNodes,
+     * d | the layout of each PtNode is described below.
+     * e |
+     * s
      *
      * f |
      * o | IF SUPPORTS_DYNAMIC_UPDATE (defined in the file header)
@@ -86,19 +86,19 @@
      * linkaddress
      */
 
-    /* Node (FusionDictionary.CharGroup) layout is as follows:
+    /* Node (FusionDictionary.PtNode) layout is as follows:
      *   | IF !SUPPORTS_DYNAMIC_UPDATE
-     *   |   addressType                         xx     : mask with MASK_GROUP_ADDRESS_TYPE
-     *   |                           2 bits, 00 = no children : FLAG_GROUP_ADDRESS_TYPE_NOADDRESS
-     * f |                                   01 = 1 byte      : FLAG_GROUP_ADDRESS_TYPE_ONEBYTE
-     * l |                                   10 = 2 bytes     : FLAG_GROUP_ADDRESS_TYPE_TWOBYTES
-     * a |                                   11 = 3 bytes     : FLAG_GROUP_ADDRESS_TYPE_THREEBYTES
+     *   |   addressType                    xx               : mask with MASK_CHILDREN_ADDRESS_TYPE
+     *   |                          2 bits, 00 = no children : FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS
+     * f |                                  01 = 1 byte      : FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE
+     * l |                                  10 = 2 bytes     : FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES
+     * a |                                  11 = 3 bytes     : FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES
      * g | ELSE
-     * s |   is moved ?              2 bits, 11 = no          : FLAG_IS_NOT_MOVED
-     *   |                              This must be the same as FLAG_GROUP_ADDRESS_TYPE_THREEBYTES
-     *   |                                   01 = yes         : FLAG_IS_MOVED
+     * s |   is moved ?             2 bits, 11 = no          : FLAG_IS_NOT_MOVED
+     *   |                            This must be the same as FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES
+     *   |                                  01 = yes         : FLAG_IS_MOVED
      *   |                        the new address is stored in the same place as the parent address
-     *   |   is deleted?                     10 = yes         : FLAG_IS_DELETED
+     *   |   is deleted?                    10 = yes         : FLAG_IS_DELETED
      *   | has several chars ?         1 bit, 1 = yes, 0 = no   : FLAG_HAS_MULTIPLE_CHARS
      *   | has a terminal ?            1 bit, 1 = yes, 0 = no   : FLAG_IS_TERMINAL
      *   | has shortcut targets ?      1 bit, 1 = yes, 0 = no   : FLAG_HAS_SHORTCUT_TARGETS
@@ -116,7 +116,7 @@
      * ddress
      *
      * c | IF FLAG_HAS_MULTIPLE_CHARS
-     * h |   char, char, char, char    n * (1 or 3 bytes) : use CharGroupInfo for i/o helpers
+     * h |   char, char, char, char    n * (1 or 3 bytes) : use PtNodeInfo for i/o helpers
      * a |   end                       1 byte, = 0
      * r | ELSE
      * s |   char                      1 or 3 bytes
@@ -127,17 +127,22 @@
      * e |   frequency                 1 byte
      * q |
      *
-     * c | IF 00 = FLAG_GROUP_ADDRESS_TYPE_NOADDRESS = addressType
-     * h |   // nothing
-     * i | ELSIF 01 = FLAG_GROUP_ADDRESS_TYPE_ONEBYTE == addressType
-     * l |   children address, 1 byte
-     * d | ELSIF 10 = FLAG_GROUP_ADDRESS_TYPE_TWOBYTES == addressType
-     * r |   children address, 2 bytes
-     * e | ELSE // 11 = FLAG_GROUP_ADDRESS_TYPE_THREEBYTES = addressType
-     * n |   children address, 3 bytes
-     * A | END
-     * d
-     * dress
+     * c | IF SUPPORTS_DYNAMIC_UPDATE
+     * h |   children address, 3 bytes
+     * i |   1 byte = bbbbbbbb match
+     * l |     case 1xxxxxxx => -((0xxxxxxx << 16) + (next byte << 8) + next byte)
+     * d |     otherwise => (bbbbbbbb<<16) + (next byte << 8) + next byte
+     * r | ELSIF 00 = FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS == addressType
+     * e |   // nothing
+     * n | ELSIF 01 = FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE == addressType
+     * A |   children address, 1 byte
+     * d | ELSIF 10 = FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES == addressType
+     * d |   children address, 2 bytes
+     * r | ELSE // 11 = FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES = addressType
+     * e |   children address, 3 bytes
+     * s | END
+     * s
+     * ress
      *
      *   | IF FLAG_IS_TERMINAL && FLAG_HAS_SHORTCUT_TARGETS
      *   | shortcut string list
@@ -156,33 +161,33 @@
      * characters which should never happen anyway (and still work, but take 3 bytes).
      *
      * bigram address list is:
-     * <flags> = | hasNext = 1 bit, 1 = yes, 0 = no     : FLAG_ATTRIBUTE_HAS_NEXT
-     *           | addressSign = 1 bit,                 : FLAG_ATTRIBUTE_OFFSET_NEGATIVE
+     * <flags> = | hasNext = 1 bit, 1 = yes, 0 = no     : FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT
+     *           | addressSign = 1 bit,                 : FLAG_BIGRAM_ATTR_OFFSET_NEGATIVE
      *           |                      1 = must take -address, 0 = must take +address
-     *           |                         xx : mask with MASK_ATTRIBUTE_ADDRESS_TYPE
-     *           | addressFormat = 2 bits, 00 = unused  : FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE
-     *           |                         01 = 1 byte  : FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE
-     *           |                         10 = 2 bytes : FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES
-     *           |                         11 = 3 bytes : FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES
-     *           | 4 bits : frequency         : mask with FLAG_ATTRIBUTE_FREQUENCY
-     * <address> | IF (01 == FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE == addressFormat)
+     *           |                         xx : mask with MASK_BIGRAM_ATTR_ADDRESS_TYPE
+     *           | addressFormat = 2 bits, 00 = unused  : FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE
+     *           |                         01 = 1 byte  : FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE
+     *           |                         10 = 2 bytes : FLAG_BIGRAM_ATTR_ADDRESS_TYPE_TWOBYTES
+     *           |                         11 = 3 bytes : FLAG_BIGRAM_ATTR_ADDRESS_TYPE_THREEBYTES
+     *           | 4 bits : frequency         : mask with FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY
+     * <address> | IF (01 == FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE == addressFormat)
      *           |   read 1 byte, add top 4 bits
-     *           | ELSIF (10 == FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES == addressFormat)
+     *           | ELSIF (10 == FLAG_BIGRAM_ATTR_ADDRESS_TYPE_TWOBYTES == addressFormat)
      *           |   read 2 bytes, add top 4 bits
-     *           | ELSE // 11 == FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES == addressFormat
+     *           | ELSE // 11 == FLAG_BIGRAM_ATTR_ADDRESS_TYPE_THREEBYTES == addressFormat
      *           |   read 3 bytes, add top 4 bits
      *           | END
-     *           | if (FLAG_ATTRIBUTE_OFFSET_NEGATIVE) then address = -address
-     * if (FLAG_ATTRIBUTE_HAS_NEXT) goto bigram_and_shortcut_address_list_is
+     *           | if (FLAG_BIGRAM_ATTR_OFFSET_NEGATIVE) then address = -address
+     * if (FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT) goto bigram_and_shortcut_address_list_is
      *
      * shortcut string list is:
-     * <byte size> = GROUP_SHORTCUT_LIST_SIZE_SIZE bytes, big-endian: size of the list, in bytes.
-     * <flags>     = | hasNext = 1 bit, 1 = yes, 0 = no : FLAG_ATTRIBUTE_HAS_NEXT
+     * <byte size> = PTNODE_SHORTCUT_LIST_SIZE_SIZE bytes, big-endian: size of the list, in bytes.
+     * <flags>     = | hasNext = 1 bit, 1 = yes, 0 = no : FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT
      *               | reserved = 3 bits, must be 0
-     *               | 4 bits : frequency : mask with FLAG_ATTRIBUTE_FREQUENCY
+     *               | 4 bits : frequency : mask with FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY
      * <shortcut>  = | string of characters at the char format described above, with the terminator
      *               | used to signal the end of the string.
-     * if (FLAG_ATTRIBUTE_HAS_NEXT goto flags
+     * if (FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT goto flags
      */
 
     public static final int MAGIC_NUMBER = 0x9BC13AFE;
@@ -206,11 +211,11 @@
     static final int FORWARD_LINK_ADDRESS_SIZE = 3;
 
     // These flags are used only in the static dictionary.
-    static final int MASK_GROUP_ADDRESS_TYPE = 0xC0;
-    static final int FLAG_GROUP_ADDRESS_TYPE_NOADDRESS = 0x00;
-    static final int FLAG_GROUP_ADDRESS_TYPE_ONEBYTE = 0x40;
-    static final int FLAG_GROUP_ADDRESS_TYPE_TWOBYTES = 0x80;
-    static final int FLAG_GROUP_ADDRESS_TYPE_THREEBYTES = 0xC0;
+    static final int MASK_CHILDREN_ADDRESS_TYPE = 0xC0;
+    static final int FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS = 0x00;
+    static final int FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE = 0x40;
+    static final int FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES = 0x80;
+    static final int FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES = 0xC0;
 
     static final int FLAG_HAS_MULTIPLE_CHARS = 0x20;
 
@@ -227,32 +232,32 @@
     static final int FLAG_IS_NOT_MOVED = 0x80 | FIXED_BIT_OF_DYNAMIC_UPDATE_MOVE;
     static final int FLAG_IS_DELETED = 0x80;
 
-    static final int FLAG_ATTRIBUTE_HAS_NEXT = 0x80;
-    static final int FLAG_ATTRIBUTE_OFFSET_NEGATIVE = 0x40;
-    static final int MASK_ATTRIBUTE_ADDRESS_TYPE = 0x30;
-    static final int FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE = 0x10;
-    static final int FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES = 0x20;
-    static final int FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES = 0x30;
-    static final int FLAG_ATTRIBUTE_FREQUENCY = 0x0F;
+    static final int FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT = 0x80;
+    static final int FLAG_BIGRAM_ATTR_OFFSET_NEGATIVE = 0x40;
+    static final int MASK_BIGRAM_ATTR_ADDRESS_TYPE = 0x30;
+    static final int FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE = 0x10;
+    static final int FLAG_BIGRAM_ATTR_ADDRESS_TYPE_TWOBYTES = 0x20;
+    static final int FLAG_BIGRAM_ATTR_ADDRESS_TYPE_THREEBYTES = 0x30;
+    static final int FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY = 0x0F;
 
-    static final int GROUP_CHARACTERS_TERMINATOR = 0x1F;
+    static final int PTNODE_CHARACTERS_TERMINATOR = 0x1F;
 
-    static final int GROUP_TERMINATOR_SIZE = 1;
-    static final int GROUP_FLAGS_SIZE = 1;
-    static final int GROUP_FREQUENCY_SIZE = 1;
-    static final int GROUP_MAX_ADDRESS_SIZE = 3;
-    static final int GROUP_ATTRIBUTE_FLAGS_SIZE = 1;
-    static final int GROUP_ATTRIBUTE_MAX_ADDRESS_SIZE = 3;
-    static final int GROUP_SHORTCUT_LIST_SIZE_SIZE = 2;
+    static final int PTNODE_TERMINATOR_SIZE = 1;
+    static final int PTNODE_FLAGS_SIZE = 1;
+    static final int PTNODE_FREQUENCY_SIZE = 1;
+    static final int PTNODE_MAX_ADDRESS_SIZE = 3;
+    static final int PTNODE_ATTRIBUTE_FLAGS_SIZE = 1;
+    static final int PTNODE_ATTRIBUTE_MAX_ADDRESS_SIZE = 3;
+    static final int PTNODE_SHORTCUT_LIST_SIZE_SIZE = 2;
 
     static final int NO_CHILDREN_ADDRESS = Integer.MIN_VALUE;
     static final int NO_PARENT_ADDRESS = 0;
     static final int NO_FORWARD_LINK_ADDRESS = 0;
     static final int INVALID_CHARACTER = -1;
 
-    static final int MAX_CHARGROUPS_FOR_ONE_BYTE_CHARGROUP_COUNT = 0x7F; // 127
-    static final int MAX_CHARGROUPS_IN_A_PT_NODE_ARRAY = 0x7FFF; // 32767
-    static final int MAX_BIGRAMS_IN_A_GROUP = 10000;
+    static final int MAX_PTNODES_FOR_ONE_BYTE_PTNODE_COUNT = 0x7F; // 127
+    static final int MAX_PTNODES_IN_A_PT_NODE_ARRAY = 0x7FFF; // 32767
+    static final int MAX_BIGRAMS_IN_A_PTNODE = 10000;
 
     static final int MAX_TERMINAL_FREQUENCY = 255;
     static final int MAX_BIGRAM_FREQUENCY = 15;
diff --git a/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java b/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java
index fce1c5c..3e685a3 100644
--- a/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java
+++ b/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java
@@ -37,15 +37,15 @@
     private static int CHARACTER_NOT_FOUND_INDEX = -1;
 
     /**
-     * A node array of the dictionary, containing several CharGroups.
+     * A node array of the dictionary, containing several PtNodes.
      *
-     * A PtNodeArray is but an ordered array of CharGroups, which essentially contain all the
+     * A PtNodeArray is but an ordered array of PtNodes, which essentially contain all the
      * real information.
      * This class also contains fields to cache size and address, to help with binary
      * generation.
      */
     public static final class PtNodeArray {
-        ArrayList<CharGroup> mData;
+        ArrayList<PtNode> mData;
         // To help with binary generation
         int mCachedSize = Integer.MIN_VALUE;
         // mCachedAddressBefore/AfterUpdate are helpers for binary dictionary generation. They
@@ -58,9 +58,9 @@
         int mCachedParentAddress = 0;
 
         public PtNodeArray() {
-            mData = new ArrayList<CharGroup>();
+            mData = new ArrayList<PtNode>();
         }
-        public PtNodeArray(ArrayList<CharGroup> data) {
+        public PtNodeArray(ArrayList<PtNode> data) {
             mData = data;
         }
     }
@@ -93,18 +93,19 @@
     }
 
     /**
-     * A group of characters, with a frequency, shortcut targets, bigrams, and children.
+     * PtNode is a group of characters, with a frequency, shortcut targets, bigrams, and children
+     * (Pt means Patricia Trie).
      *
-     * This is the central class of the in-memory representation. A CharGroup is what can
+     * This is the central class of the in-memory representation. A PtNode is what can
      * be seen as a traditional "trie node", except it can hold several characters at the
-     * same time. A CharGroup essentially represents one or several characters in the middle
+     * same time. A PtNode essentially represents one or several characters in the middle
      * of the trie tree; as such, it can be a terminal, and it can have children.
-     * In this in-memory representation, whether the CharGroup is a terminal or not is represented
+     * In this in-memory representation, whether the PtNode is a terminal or not is represented
      * in the frequency, where NOT_A_TERMINAL (= -1) means this is not a terminal and any other
      * value is the frequency of this terminal. A terminal may have non-null shortcuts and/or
      * bigrams, but a non-terminal may not. Moreover, children, if present, are null.
      */
-    public static final class CharGroup {
+    public static final class PtNode {
         public static final int NOT_A_TERMINAL = -1;
         final int mChars[];
         ArrayList<WeightedString> mShortcutTargets;
@@ -119,11 +120,11 @@
         // same time. Updating will update the AfterUpdate value, and the code will move them
         // to BeforeUpdate before the next update pass.
         // The update process does not need two versions of mCachedSize.
-        int mCachedSize; // The size, in bytes, of this char group.
-        int mCachedAddressBeforeUpdate; // The address of this char group (before update)
-        int mCachedAddressAfterUpdate; // The address of this char group (after update)
+        int mCachedSize; // The size, in bytes, of this PtNode.
+        int mCachedAddressBeforeUpdate; // The address of this PtNode (before update)
+        int mCachedAddressAfterUpdate; // The address of this PtNode (after update)
 
-        public CharGroup(final int[] chars, final ArrayList<WeightedString> shortcutTargets,
+        public PtNode(final int[] chars, final ArrayList<WeightedString> shortcutTargets,
                 final ArrayList<WeightedString> bigrams, final int frequency,
                 final boolean isNotAWord, final boolean isBlacklistEntry) {
             mChars = chars;
@@ -135,7 +136,7 @@
             mIsBlacklistEntry = isBlacklistEntry;
         }
 
-        public CharGroup(final int[] chars, final ArrayList<WeightedString> shortcutTargets,
+        public PtNode(final int[] chars, final ArrayList<WeightedString> shortcutTargets,
                 final ArrayList<WeightedString> bigrams, final int frequency,
                 final boolean isNotAWord, final boolean isBlacklistEntry,
                 final PtNodeArray children) {
@@ -148,7 +149,7 @@
             mIsBlacklistEntry = isBlacklistEntry;
         }
 
-        public void addChild(CharGroup n) {
+        public void addChild(PtNode n) {
             if (null == mChildren) {
                 mChildren = new PtNodeArray();
             }
@@ -245,7 +246,7 @@
         }
 
         /**
-         * Updates the CharGroup with the given properties. Adds the shortcut and bigram lists to
+         * Updates the PtNode with the given properties. Adds the shortcut and bigram lists to
          * the existing ones if any. Note: unigram, bigram, and shortcut frequencies are only
          * updated if they are higher than the existing ones.
          */
@@ -407,13 +408,13 @@
     }
 
     /**
-     * Sanity check for a node array.
+     * Sanity check for a PtNode array.
      *
-     * This method checks that all CharGroups in a node array are ordered as expected.
+     * This method checks that all PtNodes in a node array are ordered as expected.
      * If they are, nothing happens. If they aren't, an exception is thrown.
      */
-    private void checkStack(PtNodeArray nodeArray) {
-        ArrayList<CharGroup> stack = nodeArray.mData;
+    private void checkStack(PtNodeArray ptNodeArray) {
+        ArrayList<PtNode> stack = ptNodeArray.mData;
         int lastValue = -1;
         for (int i = 0; i < stack.size(); ++i) {
             int currentValue = stack.get(i).mChars[0];
@@ -432,18 +433,18 @@
      * @param frequency the bigram frequency
      */
     public void setBigram(final String word1, final String word2, final int frequency) {
-        CharGroup charGroup = findWordInTree(mRootNodeArray, word1);
-        if (charGroup != null) {
-            final CharGroup charGroup2 = findWordInTree(mRootNodeArray, word2);
-            if (charGroup2 == null) {
+        PtNode ptNode = findWordInTree(mRootNodeArray, word1);
+        if (ptNode != null) {
+            final PtNode ptNode2 = findWordInTree(mRootNodeArray, word2);
+            if (ptNode2 == null) {
                 add(getCodePoints(word2), 0, null, false /* isNotAWord */,
                         false /* isBlacklistEntry */);
-                // The chargroup for the first word may have moved by the above insertion,
+                // The PtNode for the first word may have moved by the above insertion,
                 // if word1 and word2 share a common stem that happens not to have been
-                // a cutting point until now. In this case, we need to refresh charGroup.
-                charGroup = findWordInTree(mRootNodeArray, word1);
+                // a cutting point until now. In this case, we need to refresh ptNode.
+                ptNode = findWordInTree(mRootNodeArray, word1);
             }
-            charGroup.addBigram(word2, frequency);
+            ptNode.addBigram(word2, frequency);
         } else {
             throw new RuntimeException("First word of bigram not found");
         }
@@ -473,84 +474,83 @@
         PtNodeArray currentNodeArray = mRootNodeArray;
         int charIndex = 0;
 
-        CharGroup currentGroup = null;
+        PtNode currentPtNode = null;
         int differentCharIndex = 0; // Set by the loop to the index of the char that differs
         int nodeIndex = findIndexOfChar(mRootNodeArray, word[charIndex]);
         while (CHARACTER_NOT_FOUND_INDEX != nodeIndex) {
-            currentGroup = currentNodeArray.mData.get(nodeIndex);
-            differentCharIndex = compareCharArrays(currentGroup.mChars, word, charIndex);
+            currentPtNode = currentNodeArray.mData.get(nodeIndex);
+            differentCharIndex = compareCharArrays(currentPtNode.mChars, word, charIndex);
             if (ARRAYS_ARE_EQUAL != differentCharIndex
-                    && differentCharIndex < currentGroup.mChars.length) break;
-            if (null == currentGroup.mChildren) break;
-            charIndex += currentGroup.mChars.length;
+                    && differentCharIndex < currentPtNode.mChars.length) break;
+            if (null == currentPtNode.mChildren) break;
+            charIndex += currentPtNode.mChars.length;
             if (charIndex >= word.length) break;
-            currentNodeArray = currentGroup.mChildren;
+            currentNodeArray = currentPtNode.mChildren;
             nodeIndex = findIndexOfChar(currentNodeArray, word[charIndex]);
         }
 
         if (CHARACTER_NOT_FOUND_INDEX == nodeIndex) {
             // No node at this point to accept the word. Create one.
             final int insertionIndex = findInsertionIndex(currentNodeArray, word[charIndex]);
-            final CharGroup newGroup = new CharGroup(
-                    Arrays.copyOfRange(word, charIndex, word.length),
+            final PtNode newPtNode = new PtNode(Arrays.copyOfRange(word, charIndex, word.length),
                     shortcutTargets, null /* bigrams */, frequency, isNotAWord, isBlacklistEntry);
-            currentNodeArray.mData.add(insertionIndex, newGroup);
+            currentNodeArray.mData.add(insertionIndex, newPtNode);
             if (DBG) checkStack(currentNodeArray);
         } else {
             // There is a word with a common prefix.
-            if (differentCharIndex == currentGroup.mChars.length) {
+            if (differentCharIndex == currentPtNode.mChars.length) {
                 if (charIndex + differentCharIndex >= word.length) {
                     // The new word is a prefix of an existing word, but the node on which it
-                    // should end already exists as is. Since the old CharGroup was not a terminal,
+                    // should end already exists as is. Since the old PtNode was not a terminal,
                     // make it one by filling in its frequency and other attributes
-                    currentGroup.update(frequency, shortcutTargets, null, isNotAWord,
+                    currentPtNode.update(frequency, shortcutTargets, null, isNotAWord,
                             isBlacklistEntry);
                 } else {
                     // The new word matches the full old word and extends past it.
                     // We only have to create a new node and add it to the end of this.
-                    final CharGroup newNode = new CharGroup(
+                    final PtNode newNode = new PtNode(
                             Arrays.copyOfRange(word, charIndex + differentCharIndex, word.length),
                                     shortcutTargets, null /* bigrams */, frequency, isNotAWord,
                                     isBlacklistEntry);
-                    currentGroup.mChildren = new PtNodeArray();
-                    currentGroup.mChildren.mData.add(newNode);
+                    currentPtNode.mChildren = new PtNodeArray();
+                    currentPtNode.mChildren.mData.add(newNode);
                 }
             } else {
                 if (0 == differentCharIndex) {
                     // Exact same word. Update the frequency if higher. This will also add the
                     // new shortcuts to the existing shortcut list if it already exists.
-                    currentGroup.update(frequency, shortcutTargets, null,
-                            currentGroup.mIsNotAWord && isNotAWord,
-                            currentGroup.mIsBlacklistEntry || isBlacklistEntry);
+                    currentPtNode.update(frequency, shortcutTargets, null,
+                            currentPtNode.mIsNotAWord && isNotAWord,
+                            currentPtNode.mIsBlacklistEntry || isBlacklistEntry);
                 } else {
                     // Partial prefix match only. We have to replace the current node with a node
                     // containing the current prefix and create two new ones for the tails.
                     PtNodeArray newChildren = new PtNodeArray();
-                    final CharGroup newOldWord = new CharGroup(
-                            Arrays.copyOfRange(currentGroup.mChars, differentCharIndex,
-                                    currentGroup.mChars.length), currentGroup.mShortcutTargets,
-                            currentGroup.mBigrams, currentGroup.mFrequency,
-                            currentGroup.mIsNotAWord, currentGroup.mIsBlacklistEntry,
-                            currentGroup.mChildren);
+                    final PtNode newOldWord = new PtNode(
+                            Arrays.copyOfRange(currentPtNode.mChars, differentCharIndex,
+                                    currentPtNode.mChars.length), currentPtNode.mShortcutTargets,
+                            currentPtNode.mBigrams, currentPtNode.mFrequency,
+                            currentPtNode.mIsNotAWord, currentPtNode.mIsBlacklistEntry,
+                            currentPtNode.mChildren);
                     newChildren.mData.add(newOldWord);
 
-                    final CharGroup newParent;
+                    final PtNode newParent;
                     if (charIndex + differentCharIndex >= word.length) {
-                        newParent = new CharGroup(
-                                Arrays.copyOfRange(currentGroup.mChars, 0, differentCharIndex),
+                        newParent = new PtNode(
+                                Arrays.copyOfRange(currentPtNode.mChars, 0, differentCharIndex),
                                 shortcutTargets, null /* bigrams */, frequency,
                                 isNotAWord, isBlacklistEntry, newChildren);
                     } else {
-                        newParent = new CharGroup(
-                                Arrays.copyOfRange(currentGroup.mChars, 0, differentCharIndex),
+                        newParent = new PtNode(
+                                Arrays.copyOfRange(currentPtNode.mChars, 0, differentCharIndex),
                                 null /* shortcutTargets */, null /* bigrams */, -1,
                                 false /* isNotAWord */, false /* isBlacklistEntry */, newChildren);
-                        final CharGroup newWord = new CharGroup(Arrays.copyOfRange(word,
+                        final PtNode newWord = new PtNode(Arrays.copyOfRange(word,
                                 charIndex + differentCharIndex, word.length),
                                 shortcutTargets, null /* bigrams */, frequency,
                                 isNotAWord, isBlacklistEntry);
                         final int addIndex = word[charIndex + differentCharIndex]
-                                > currentGroup.mChars[differentCharIndex] ? 1 : 0;
+                                > currentPtNode.mChars[differentCharIndex] ? 1 : 0;
                         newChildren.mData.add(addIndex, newWord);
                     }
                     currentNodeArray.mData.set(nodeIndex, newParent);
@@ -589,29 +589,29 @@
     }
 
     /**
-     * Helper class that compares and sorts two chargroups according to their
+     * Helper class that compares and sorts two PtNodes according to their
      * first element only. I repeat: ONLY the first element is considered, the rest
      * is ignored.
      * This comparator imposes orderings that are inconsistent with equals.
      */
-    static private final class CharGroupComparator implements java.util.Comparator<CharGroup> {
+    static private final class PtNodeComparator implements java.util.Comparator<PtNode> {
         @Override
-        public int compare(CharGroup c1, CharGroup c2) {
-            if (c1.mChars[0] == c2.mChars[0]) return 0;
-            return c1.mChars[0] < c2.mChars[0] ? -1 : 1;
+        public int compare(PtNode p1, PtNode p2) {
+            if (p1.mChars[0] == p2.mChars[0]) return 0;
+            return p1.mChars[0] < p2.mChars[0] ? -1 : 1;
         }
     }
-    final static private CharGroupComparator CHARGROUP_COMPARATOR = new CharGroupComparator();
+    final static private PtNodeComparator PTNODE_COMPARATOR = new PtNodeComparator();
 
     /**
      * Finds the insertion index of a character within a node array.
      */
     private static int findInsertionIndex(final PtNodeArray nodeArray, int character) {
-        final ArrayList<CharGroup> data = nodeArray.mData;
-        final CharGroup reference = new CharGroup(new int[] { character },
+        final ArrayList<PtNode> data = nodeArray.mData;
+        final PtNode reference = new PtNode(new int[] { character },
                 null /* shortcutTargets */, null /* bigrams */, 0, false /* isNotAWord */,
                 false /* isBlacklistEntry */);
-        int result = Collections.binarySearch(data, reference, CHARGROUP_COMPARATOR);
+        int result = Collections.binarySearch(data, reference, PTNODE_COMPARATOR);
         return result >= 0 ? result : -result - 1;
     }
 
@@ -633,35 +633,37 @@
      * Helper method to find a word in a given branch.
      */
     @SuppressWarnings("unused")
-    public static CharGroup findWordInTree(PtNodeArray nodeArray, final String string) {
+    public static PtNode findWordInTree(PtNodeArray nodeArray, final String string) {
         int index = 0;
         final StringBuilder checker = DBG ? new StringBuilder() : null;
         final int[] codePoints = getCodePoints(string);
 
-        CharGroup currentGroup;
+        PtNode currentPtNode;
         do {
             int indexOfGroup = findIndexOfChar(nodeArray, codePoints[index]);
             if (CHARACTER_NOT_FOUND_INDEX == indexOfGroup) return null;
-            currentGroup = nodeArray.mData.get(indexOfGroup);
+            currentPtNode = nodeArray.mData.get(indexOfGroup);
 
-            if (codePoints.length - index < currentGroup.mChars.length) return null;
+            if (codePoints.length - index < currentPtNode.mChars.length) return null;
             int newIndex = index;
-            while (newIndex < codePoints.length && newIndex - index < currentGroup.mChars.length) {
-                if (currentGroup.mChars[newIndex - index] != codePoints[newIndex]) return null;
+            while (newIndex < codePoints.length && newIndex - index < currentPtNode.mChars.length) {
+                if (currentPtNode.mChars[newIndex - index] != codePoints[newIndex]) return null;
                 newIndex++;
             }
             index = newIndex;
 
-            if (DBG) checker.append(new String(currentGroup.mChars, 0, currentGroup.mChars.length));
+            if (DBG) {
+                checker.append(new String(currentPtNode.mChars, 0, currentPtNode.mChars.length));
+            }
             if (index < codePoints.length) {
-                nodeArray = currentGroup.mChildren;
+                nodeArray = currentPtNode.mChildren;
             }
         } while (null != nodeArray && index < codePoints.length);
 
         if (index < codePoints.length) return null;
-        if (!currentGroup.isTerminal()) return null;
+        if (!currentPtNode.isTerminal()) return null;
         if (DBG && !string.equals(checker.toString())) return null;
-        return currentGroup;
+        return currentPtNode;
     }
 
     /**
@@ -675,18 +677,18 @@
     }
 
     /**
-     * Recursively count the number of character groups in a given branch of the trie.
+     * Recursively count the number of PtNodes in a given branch of the trie.
      *
      * @param nodeArray the parent node.
-     * @return the number of char groups in all the branch under this node.
+     * @return the number of PtNodes in all the branch under this node.
      */
-    public static int countCharGroups(final PtNodeArray nodeArray) {
+    public static int countPtNodes(final PtNodeArray nodeArray) {
         final int nodeSize = nodeArray.mData.size();
         int size = nodeSize;
         for (int i = nodeSize - 1; i >= 0; --i) {
-            CharGroup group = nodeArray.mData.get(i);
-            if (null != group.mChildren)
-                size += countCharGroups(group.mChildren);
+            PtNode ptNode = nodeArray.mData.get(i);
+            if (null != ptNode.mChildren)
+                size += countPtNodes(ptNode.mChildren);
         }
         return size;
     }
@@ -700,9 +702,9 @@
     public static int countNodeArrays(final PtNodeArray nodeArray) {
         int size = 1;
         for (int i = nodeArray.mData.size() - 1; i >= 0; --i) {
-            CharGroup group = nodeArray.mData.get(i);
-            if (null != group.mChildren)
-                size += countNodeArrays(group.mChildren);
+            PtNode ptNode = nodeArray.mData.get(i);
+            if (null != ptNode.mChildren)
+                size += countNodeArrays(ptNode.mChildren);
         }
         return size;
     }
@@ -713,9 +715,9 @@
     private static boolean hasBigramsInternal(final PtNodeArray nodeArray) {
         if (null == nodeArray) return false;
         for (int i = nodeArray.mData.size() - 1; i >= 0; --i) {
-            CharGroup group = nodeArray.mData.get(i);
-            if (null != group.mBigrams) return true;
-            if (hasBigramsInternal(group.mChildren)) return true;
+            PtNode ptNode = nodeArray.mData.get(i);
+            if (null != ptNode.mBigrams) return true;
+            if (hasBigramsInternal(ptNode.mChildren)) return true;
         }
         return false;
     }
@@ -748,8 +750,8 @@
         MakedictLog.i("Do not merge tails");
         return;
 
-//        MakedictLog.i("Merging nodes. Number of nodes : " + countNodes(root));
-//        MakedictLog.i("Number of groups : " + countCharGroups(root));
+//        MakedictLog.i("Merging PtNodes. Number of PtNodes : " + countPtNodes(root));
+//        MakedictLog.i("Number of PtNodes : " + countPtNodes(root));
 //
 //        final HashMap<String, ArrayList<PtNodeArray>> repository =
 //                  new HashMap<String, ArrayList<PtNodeArray>>();
@@ -771,25 +773,25 @@
 //       if (a.data.size() != b.data.size()) return false;
 //       final int size = a.data.size();
 //       for (int i = size - 1; i >= 0; --i) {
-//           CharGroup aGroup = a.data.get(i);
-//           CharGroup bGroup = b.data.get(i);
-//           if (aGroup.frequency != bGroup.frequency) return false;
-//           if (aGroup.alternates == null && bGroup.alternates != null) return false;
-//           if (aGroup.alternates != null && !aGroup.equals(bGroup.alternates)) return false;
-//           if (!Arrays.equals(aGroup.chars, bGroup.chars)) return false;
-//           if (!isEqual(aGroup.children, bGroup.children)) return false;
+//           PtNode aPtNode = a.data.get(i);
+//           PtNode bPtNode = b.data.get(i);
+//           if (aPtNode.frequency != bPtNode.frequency) return false;
+//           if (aPtNode.alternates == null && bPtNode.alternates != null) return false;
+//           if (aPtNode.alternates != null && !aPtNode.equals(bPtNode.alternates)) return false;
+//           if (!Arrays.equals(aPtNode.chars, bPtNode.chars)) return false;
+//           if (!isEqual(aPtNode.children, bPtNode.children)) return false;
 //       }
 //       return true;
 //   }
 
 //   static private HashMap<String, ArrayList<PtNodeArray>> mergeTailsInner(
 //           final HashMap<String, ArrayList<PtNodeArray>> map, final PtNodeArray nodeArray) {
-//       final ArrayList<CharGroup> branches = nodeArray.data;
+//       final ArrayList<PtNode> branches = nodeArray.data;
 //       final int nodeSize = branches.size();
 //       for (int i = 0; i < nodeSize; ++i) {
-//           CharGroup group = branches.get(i);
-//           if (null != group.children) {
-//               String pseudoHash = getPseudoHash(group.children);
+//           PtNode ptNode = branches.get(i);
+//           if (null != ptNode.children) {
+//               String pseudoHash = getPseudoHash(ptNode.children);
 //               ArrayList<PtNodeArray> similarList = map.get(pseudoHash);
 //               if (null == similarList) {
 //                   similarList = new ArrayList<PtNodeArray>();
@@ -797,16 +799,16 @@
 //               }
 //               boolean merged = false;
 //               for (PtNodeArray similar : similarList) {
-//                   if (isEqual(group.children, similar)) {
-//                       group.children = similar;
+//                   if (isEqual(ptNode.children, similar)) {
+//                       ptNode.children = similar;
 //                       merged = true;
 //                       break;
 //                   }
 //               }
 //               if (!merged) {
-//                   similarList.add(group.children);
+//                   similarList.add(ptNode.children);
 //               }
-//               mergeTailsInner(map, group.children);
+//               mergeTailsInner(map, ptNode.children);
 //           }
 //       }
 //       return map;
@@ -814,9 +816,9 @@
 
 //  private static String getPseudoHash(final PtNodeArray nodeArray) {
 //      StringBuilder s = new StringBuilder();
-//      for (CharGroup g : nodeArray.data) {
-//          s.append(g.frequency);
-//          for (int ch : g.chars) {
+//      for (PtNode ptNode : nodeArray.data) {
+//          s.append(ptNode.frequency);
+//          for (int ch : ptNode.chars) {
 //              s.append(Character.toChars(ch));
 //          }
 //      }
@@ -830,20 +832,20 @@
      */
     public static final class DictionaryIterator implements Iterator<Word> {
         private static final class Position {
-            public Iterator<CharGroup> pos;
+            public Iterator<PtNode> pos;
             public int length;
-            public Position(ArrayList<CharGroup> groups) {
-                pos = groups.iterator();
+            public Position(ArrayList<PtNode> ptNodes) {
+                pos = ptNodes.iterator();
                 length = 0;
             }
         }
         final StringBuilder mCurrentString;
         final LinkedList<Position> mPositions;
 
-        public DictionaryIterator(ArrayList<CharGroup> root) {
+        public DictionaryIterator(ArrayList<PtNode> ptRoot) {
             mCurrentString = new StringBuilder();
             mPositions = new LinkedList<Position>();
-            final Position rootPos = new Position(root);
+            final Position rootPos = new Position(ptRoot);
             mPositions.add(rootPos);
         }
 
@@ -864,20 +866,20 @@
 
             do {
                 if (currentPos.pos.hasNext()) {
-                    final CharGroup currentGroup = currentPos.pos.next();
+                    final PtNode currentPtNode = currentPos.pos.next();
                     currentPos.length = mCurrentString.length();
-                    for (int i : currentGroup.mChars) {
+                    for (int i : currentPtNode.mChars) {
                         mCurrentString.append(Character.toChars(i));
                     }
-                    if (null != currentGroup.mChildren) {
-                        currentPos = new Position(currentGroup.mChildren.mData);
+                    if (null != currentPtNode.mChildren) {
+                        currentPos = new Position(currentPtNode.mChildren.mData);
                         currentPos.length = mCurrentString.length();
                         mPositions.addLast(currentPos);
                     }
-                    if (currentGroup.mFrequency >= 0) {
-                        return new Word(mCurrentString.toString(), currentGroup.mFrequency,
-                                currentGroup.mShortcutTargets, currentGroup.mBigrams,
-                                currentGroup.mIsNotAWord, currentGroup.mIsBlacklistEntry);
+                    if (currentPtNode.mFrequency >= 0) {
+                        return new Word(mCurrentString.toString(), currentPtNode.mFrequency,
+                                currentPtNode.mShortcutTargets, currentPtNode.mBigrams,
+                                currentPtNode.mIsNotAWord, currentPtNode.mIsBlacklistEntry);
                     }
                 } else {
                     mPositions.removeLast();
diff --git a/java/src/com/android/inputmethod/latin/makedict/CharGroupInfo.java b/java/src/com/android/inputmethod/latin/makedict/PtNodeInfo.java
similarity index 88%
rename from java/src/com/android/inputmethod/latin/makedict/CharGroupInfo.java
rename to java/src/com/android/inputmethod/latin/makedict/PtNodeInfo.java
index b361744..188de7a 100644
--- a/java/src/com/android/inputmethod/latin/makedict/CharGroupInfo.java
+++ b/java/src/com/android/inputmethod/latin/makedict/PtNodeInfo.java
@@ -21,9 +21,9 @@
 import java.util.ArrayList;
 
 /**
- * Raw char group info straight out of a file. This will contain numbers for addresses.
+ * Raw PtNode info straight out of a file. This will contain numbers for addresses.
  */
-public final class CharGroupInfo {
+public final class PtNodeInfo {
 
     public final int mOriginalAddress;
     public final int mEndAddress;
@@ -35,7 +35,7 @@
     public final ArrayList<WeightedString> mShortcutTargets;
     public final ArrayList<PendingAttribute> mBigrams;
 
-    public CharGroupInfo(final int originalAddress, final int endAddress, final int flags,
+    public PtNodeInfo(final int originalAddress, final int endAddress, final int flags,
             final int[] characters, final int frequency, final int parentAddress,
             final int childrenAddress, final ArrayList<WeightedString> shortcutTargets,
             final ArrayList<PendingAttribute> bigrams) {
diff --git a/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java
index f655e30..51e101f 100644
--- a/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java
@@ -21,7 +21,7 @@
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer;
 import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
-import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
+import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
 import com.android.inputmethod.latin.utils.JniUtils;
 
@@ -99,14 +99,14 @@
                 if (address == 0) return FormatSpec.NO_CHILDREN_ADDRESS;
                 return address;
             } else {
-                switch (optionFlags & FormatSpec.MASK_GROUP_ADDRESS_TYPE) {
-                    case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_ONEBYTE:
+                switch (optionFlags & FormatSpec.MASK_CHILDREN_ADDRESS_TYPE) {
+                    case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE:
                         return dictBuffer.readUnsignedByte();
-                    case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_TWOBYTES:
+                    case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES:
                         return dictBuffer.readUnsignedShort();
-                    case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_THREEBYTES:
+                    case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES:
                         return dictBuffer.readUnsignedInt24();
-                    case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_NOADDRESS:
+                    case FormatSpec.FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS:
                     default:
                         return FormatSpec.NO_CHILDREN_ADDRESS;
                 }
@@ -122,8 +122,8 @@
                 final int targetFlags = dictBuffer.readUnsignedByte();
                 final String word = CharEncoding.readString(dictBuffer);
                 shortcutTargets.add(new WeightedString(word,
-                        targetFlags & FormatSpec.FLAG_ATTRIBUTE_FREQUENCY));
-                if (0 == (targetFlags & FormatSpec.FLAG_ATTRIBUTE_HAS_NEXT)) break;
+                        targetFlags & FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY));
+                if (0 == (targetFlags & FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT)) break;
             }
             return dictBuffer.position() - pointerBefore;
         }
@@ -132,22 +132,22 @@
                 final ArrayList<PendingAttribute> bigrams, final int baseAddress) {
             int readLength = 0;
             int bigramCount = 0;
-            while (bigramCount++ < FormatSpec.MAX_BIGRAMS_IN_A_GROUP) {
+            while (bigramCount++ < FormatSpec.MAX_BIGRAMS_IN_A_PTNODE) {
                 final int bigramFlags = dictBuffer.readUnsignedByte();
                 ++readLength;
-                final int sign = 0 == (bigramFlags & FormatSpec.FLAG_ATTRIBUTE_OFFSET_NEGATIVE)
+                final int sign = 0 == (bigramFlags & FormatSpec.FLAG_BIGRAM_ATTR_OFFSET_NEGATIVE)
                         ? 1 : -1;
                 int bigramAddress = baseAddress + readLength;
-                switch (bigramFlags & FormatSpec.MASK_ATTRIBUTE_ADDRESS_TYPE) {
-                    case FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE:
+                switch (bigramFlags & FormatSpec.MASK_BIGRAM_ATTR_ADDRESS_TYPE) {
+                    case FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE:
                         bigramAddress += sign * dictBuffer.readUnsignedByte();
                         readLength += 1;
                         break;
-                    case FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES:
+                    case FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_TWOBYTES:
                         bigramAddress += sign * dictBuffer.readUnsignedShort();
                         readLength += 2;
                         break;
-                    case FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES:
+                    case FormatSpec.FLAG_BIGRAM_ATTR_ADDRESS_TYPE_THREEBYTES:
                         final int offset = (dictBuffer.readUnsignedByte() << 16)
                                 + dictBuffer.readUnsignedShort();
                         bigramAddress += sign * offset;
@@ -156,9 +156,10 @@
                     default:
                         throw new RuntimeException("Has bigrams with no address");
                 }
-                bigrams.add(new PendingAttribute(bigramFlags & FormatSpec.FLAG_ATTRIBUTE_FREQUENCY,
+                bigrams.add(new PendingAttribute(
+                        bigramFlags & FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY,
                         bigramAddress));
-                if (0 == (bigramFlags & FormatSpec.FLAG_ATTRIBUTE_HAS_NEXT)) break;
+                if (0 == (bigramFlags & FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT)) break;
             }
             return readLength;
         }
@@ -236,7 +237,7 @@
     // TODO: Make this buffer multi thread safe.
     private final int[] mCharacterBuffer = new int[FormatSpec.MAX_WORD_LENGTH];
     @Override
-    public CharGroupInfo readPtNode(final int ptNodePos, final FormatOptions options) {
+    public PtNodeInfo readPtNode(final int ptNodePos, final FormatOptions options) {
         int addressPointer = ptNodePos;
         final int flags = PtNodeReader.readPtNodeOptionFlags(mDictBuffer);
         ++addressPointer;
@@ -270,7 +271,7 @@
             ++addressPointer;
             frequency = PtNodeReader.readFrequency(mDictBuffer);
         } else {
-            frequency = CharGroup.NOT_A_TERMINAL;
+            frequency = PtNode.NOT_A_TERMINAL;
         }
         int childrenAddress = PtNodeReader.readChildrenAddress(mDictBuffer, flags, options);
         if (childrenAddress != FormatSpec.NO_CHILDREN_ADDRESS) {
@@ -290,14 +291,13 @@
         if (0 != (flags & FormatSpec.FLAG_HAS_BIGRAMS)) {
             bigrams = new ArrayList<PendingAttribute>();
             addressPointer += PtNodeReader.readBigrams(mDictBuffer, bigrams, addressPointer);
-            if (bigrams.size() >= FormatSpec.MAX_BIGRAMS_IN_A_GROUP) {
-                MakedictLog.d("too many bigrams in a group.");
+            if (bigrams.size() >= FormatSpec.MAX_BIGRAMS_IN_A_PTNODE) {
+                MakedictLog.d("too many bigrams in a PtNode.");
             }
         } else {
             bigrams = null;
         }
-
-        return new CharGroupInfo(ptNodePos, addressPointer, flags, characters, frequency,
+        return new PtNodeInfo(ptNodePos, addressPointer, flags, characters, frequency,
                 parentAddress, childrenAddress, shortcutTargets, bigrams);
     }
 
diff --git a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java
index 6d4c05e..98f06a6 100644
--- a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java
+++ b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java
@@ -25,7 +25,7 @@
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer;
 import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
-import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
+import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
 import com.android.inputmethod.latin.utils.ByteArrayDictBuffer;
@@ -239,17 +239,17 @@
 
         // check unigram
         for (final String word : words) {
-            final CharGroup cg = FusionDictionary.findWordInTree(dict.mRootNodeArray, word);
-            assertNotNull(cg);
+            final PtNode ptNode = FusionDictionary.findWordInTree(dict.mRootNodeArray, word);
+            assertNotNull(ptNode);
         }
 
         // check bigram
         for (int i = 0; i < bigrams.size(); ++i) {
             final int w1 = bigrams.keyAt(i);
             for (final int w2 : bigrams.valueAt(i)) {
-                final CharGroup cg = FusionDictionary.findWordInTree(dict.mRootNodeArray,
+                final PtNode ptNode = FusionDictionary.findWordInTree(dict.mRootNodeArray,
                         words.get(w1));
-                assertNotNull(words.get(w1) + "," + words.get(w2), cg.getBigram(words.get(w2)));
+                assertNotNull(words.get(w1) + "," + words.get(w2), ptNode.getBigram(words.get(w2)));
             }
         }
 
@@ -257,11 +257,11 @@
         if (shortcutMap != null) {
             for (final Map.Entry<String, List<String>> entry : shortcutMap.entrySet()) {
                 assertTrue(words.contains(entry.getKey()));
-                final CharGroup group = FusionDictionary.findWordInTree(dict.mRootNodeArray,
+                final PtNode ptNode = FusionDictionary.findWordInTree(dict.mRootNodeArray,
                         entry.getKey());
                 for (final String word : entry.getValue()) {
                     assertNotNull("shortcut not found: " + entry.getKey() + ", " + word,
-                            group.getShortcut(word));
+                            ptNode.getShortcut(word));
                 }
             }
         }
diff --git a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtilsTests.java b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtilsTests.java
index 901cfdb..be9323b 100644
--- a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtilsTests.java
+++ b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtilsTests.java
@@ -86,8 +86,8 @@
         return builder.toString();
     }
 
-    private static void printCharGroup(final CharGroupInfo info) {
-        Log.d(TAG, "    CharGroup at " + info.mOriginalAddress);
+    private static void printPtNode(final PtNodeInfo info) {
+        Log.d(TAG, "    PtNode at " + info.mOriginalAddress);
         Log.d(TAG, "        flags = " + info.mFlags);
         Log.d(TAG, "        parentAddress = " + info.mParentAddress);
         Log.d(TAG, "        characters = " + new String(info.mCharacters, 0,
@@ -115,12 +115,12 @@
             final FormatSpec.FormatOptions formatOptions) {
         final DictBuffer dictBuffer = dictDecoder.getDictBuffer();
         Log.d(TAG, "Node at " + dictBuffer.position());
-        final int count = BinaryDictDecoderUtils.readCharGroupCount(dictBuffer);
-        Log.d(TAG, "    charGroupCount = " + count);
+        final int count = BinaryDictDecoderUtils.readPtNodeCount(dictBuffer);
+        Log.d(TAG, "    ptNodeCount = " + count);
         for (int i = 0; i < count; ++i) {
-            final CharGroupInfo currentInfo = dictDecoder.readPtNode(dictBuffer.position(),
+            final PtNodeInfo currentInfo = dictDecoder.readPtNode(dictBuffer.position(),
                     formatOptions);
-            printCharGroup(currentInfo);
+            printPtNode(currentInfo);
         }
         if (formatOptions.mSupportsDynamicUpdate) {
             final int forwardLinkAddress = dictBuffer.readUnsignedInt24();
@@ -155,11 +155,11 @@
      *
      * @param dictDecoder the dict decoder
      * @param word the word searched
-     * @return the found group
+     * @return the found ptNodeInfo
      * @throws IOException
      * @throws UnsupportedFormatException
      */
-    private static CharGroupInfo findWordByBinaryDictReader(final Ver3DictDecoder dictDecoder,
+    private static PtNodeInfo findWordByBinaryDictReader(final Ver3DictDecoder dictDecoder,
             final String word) throws IOException, UnsupportedFormatException {
         int position = BinaryDictIOUtils.getTerminalPosition(dictDecoder, word);
         final DictBuffer dictBuffer = dictDecoder.getDictBuffer();
@@ -172,10 +172,10 @@
         return null;
     }
 
-    private CharGroupInfo findWordFromFile(final File file, final String word) {
-        CharGroupInfo info = null;
+    private PtNodeInfo findWordFromFile(final File file, final String word) {
+        final Ver3DictDecoder dictDecoder = new Ver3DictDecoder(file);
+        PtNodeInfo info = null;
         try {
-            final Ver3DictDecoder dictDecoder = new Ver3DictDecoder(file);
             dictDecoder.openDictBuffer();
             info = findWordByBinaryDictReader(dictDecoder, word);
         } catch (IOException e) {
@@ -328,7 +328,7 @@
         insertAndCheckWord(file, "banana", 0, false, null, null);
         insertAndCheckWord(file, "recursive", 60, true, banana, null);
 
-        final CharGroupInfo info = findWordFromFile(file, "recursive");
+        final PtNodeInfo info = findWordFromFile(file, "recursive");
         int bananaPos = getWordPosition(file, "banana");
         assertNotNull(info.mBigrams);
         assertEquals(info.mBigrams.size(), 1);
diff --git a/tests/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtilsTests.java b/tests/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtilsTests.java
index 8831df9..72b9478 100644
--- a/tests/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtilsTests.java
+++ b/tests/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtilsTests.java
@@ -25,7 +25,7 @@
 import com.android.inputmethod.latin.makedict.DictEncoder;
 import com.android.inputmethod.latin.makedict.FormatSpec;
 import com.android.inputmethod.latin.makedict.FusionDictionary;
-import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
+import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.Ver3DictDecoder;
 import com.android.inputmethod.latin.makedict.Ver3DictEncoder;
 import com.android.inputmethod.latin.personalization.UserHistoryDictionaryBigramList;
@@ -89,12 +89,12 @@
 
     private void checkWordInFusionDict(final FusionDictionary dict, final String word,
             final ArrayList<String> expectedBigrams) {
-        final CharGroup group = FusionDictionary.findWordInTree(dict.mRootNodeArray, word);
-        assertNotNull(group);
-        assertTrue(group.isTerminal());
+        final PtNode ptNode = FusionDictionary.findWordInTree(dict.mRootNodeArray, word);
+        assertNotNull(ptNode);
+        assertTrue(ptNode.isTerminal());
 
         for (final String bigram : expectedBigrams) {
-            assertNotNull(group.getBigram(bigram));
+            assertNotNull(ptNode.getBigram(bigram));
         }
     }
 
diff --git a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Diff.java b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Diff.java
index d790d06..66fd084 100644
--- a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Diff.java
+++ b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Diff.java
@@ -17,7 +17,7 @@
 package com.android.inputmethod.latin.dicttool;
 
 import com.android.inputmethod.latin.makedict.FusionDictionary;
-import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
+import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
 import com.android.inputmethod.latin.makedict.Word;
 
@@ -121,7 +121,7 @@
     private static void diffWords(final FusionDictionary dict0, final FusionDictionary dict1) {
         boolean hasDifferences = false;
         for (final Word word0 : dict0) {
-            final CharGroup word1 = FusionDictionary.findWordInTree(dict1.mRootNodeArray,
+            final PtNode word1 = FusionDictionary.findWordInTree(dict1.mRootNodeArray,
                     word0.mWord);
             if (null == word1) {
                 // This word is not in dict1
@@ -151,7 +151,7 @@
             }
         }
         for (final Word word1 : dict1) {
-            final CharGroup word0 = FusionDictionary.findWordInTree(dict0.mRootNodeArray,
+            final PtNode word0 = FusionDictionary.findWordInTree(dict0.mRootNodeArray,
                     word1.mWord);
             if (null == word0) {
                 // This word is not in dict0
diff --git a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Info.java b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Info.java
index fa8c5f7..350f427 100644
--- a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Info.java
+++ b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Info.java
@@ -18,7 +18,7 @@
 
 import com.android.inputmethod.latin.makedict.FormatSpec;
 import com.android.inputmethod.latin.makedict.FusionDictionary;
-import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
+import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
 import com.android.inputmethod.latin.makedict.Word;
 
@@ -65,20 +65,20 @@
 
     private static void showWordInfo(final FusionDictionary dict, final String word,
             final boolean plumbing) {
-        final CharGroup group = FusionDictionary.findWordInTree(dict.mRootNodeArray, word);
-        if (null == group) {
+        final PtNode ptNode = FusionDictionary.findWordInTree(dict.mRootNodeArray, word);
+        if (null == ptNode) {
             System.out.println(word + " is not in the dictionary");
             return;
         }
         System.out.println("Word: " + word);
-        System.out.println("  Freq: " + group.getFrequency());
-        if (group.getIsNotAWord()) {
+        System.out.println("  Freq: " + ptNode.getFrequency());
+        if (ptNode.getIsNotAWord()) {
             System.out.println("  Is not a word");
         }
-        if (group.getIsBlacklistEntry()) {
+        if (ptNode.getIsBlacklistEntry()) {
             System.out.println("  Is a blacklist entry");
         }
-        final ArrayList<WeightedString> shortcutTargets = group.getShortcutTargets();
+        final ArrayList<WeightedString> shortcutTargets = ptNode.getShortcutTargets();
         if (null == shortcutTargets || shortcutTargets.isEmpty()) {
             System.out.println("  No shortcuts");
         } else {
@@ -88,7 +88,7 @@
                                 ? "whitelist" : shortcutTarget.mFrequency) + ")");
             }
         }
-        final ArrayList<WeightedString> bigrams = group.getBigrams();
+        final ArrayList<WeightedString> bigrams = ptNode.getBigrams();
         if (null == bigrams || bigrams.isEmpty()) {
             System.out.println("  No bigrams");
         } else {
diff --git a/tools/dicttool/tests/com/android/inputmethod/latin/makedict/FusionDictionaryTest.java b/tools/dicttool/tests/com/android/inputmethod/latin/makedict/FusionDictionaryTest.java
index 22c0ceb..659650a 100644
--- a/tools/dicttool/tests/com/android/inputmethod/latin/makedict/FusionDictionaryTest.java
+++ b/tools/dicttool/tests/com/android/inputmethod/latin/makedict/FusionDictionaryTest.java
@@ -17,7 +17,7 @@
 package com.android.inputmethod.latin.makedict;
 
 import com.android.inputmethod.latin.makedict.FusionDictionary;
-import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
+import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
 import com.android.inputmethod.latin.makedict.Word;
@@ -72,8 +72,8 @@
         assertNotNull(dict);
         for (final String word : words) {
             if (--limit < 0) return;
-            final CharGroup cg = FusionDictionary.findWordInTree(dict.mRootNodeArray, word);
-            assertNotNull(cg);
+            final PtNode ptNode = FusionDictionary.findWordInTree(dict.mRootNodeArray, word);
+            assertNotNull(ptNode);
         }
     }