Update runtime files.
diff --git a/runtime/doc/sign.txt b/runtime/doc/sign.txt
index 7b33a2d..4886f74 100644
--- a/runtime/doc/sign.txt
+++ b/runtime/doc/sign.txt
@@ -1,4 +1,4 @@
-*sign.txt*      For Vim version 8.1.  Last change: 2019 Jan 06
+*sign.txt*      For Vim version 8.1.  Last change: 2019 Jan 17
 
 
 		  VIM REFERENCE MANUAL    by Gordon Prieur
@@ -31,7 +31,7 @@
 Signs and highlights are not useful just for debuggers.  Sun's Visual
 WorkShop uses signs and highlights to mark build errors and SourceBrowser
 hits.  Additionally, the debugger supports 8 to 10 different signs and
-highlight colors. |workshop|  Same for Netbeans |netbeans|.
+highlight colors, see |NetBeans|.
 
 There are two steps in using signs:
 
@@ -43,6 +43,7 @@
    displayed.  A defined sign can be placed several times in different lines
    and files.
 
+							*sign-column*
 When signs are defined for a file, Vim will automatically add a column of two
 characters to display them in.  When the last sign is unplaced the column
 disappears again.  This behavior can be changed with the 'signcolumn' option.
@@ -55,7 +56,7 @@
 							*sign-identifier*
 Each placed sign is identified by a number called the sign identifier. This
 identifier is used to jump to the sign or to remove the sign. The identifier
-is assigned when placing the sign using the |sign-place| command or the
+is assigned when placing the sign using the |:sign-place| command or the
 |sign_place()| function. Each sign identifier should be a unique number. If
 multiple placed signs use the same identifier, then jumping to or removing a
 sign becomes unpredictable. To avoid overlapping identifiers, sign groups can
@@ -76,6 +77,10 @@
 independent of the sign group. The default priority for a sign is 10. The
 priority is assigned at the time of placing a sign.
 
+When the line on which the sign is placed is deleted, the sign is moved to the
+next line (or the last line of the buffer, if there is no next line).  When
+the delete is undone the sign does not move back.
+
 ==============================================================================
 2. Commands					*sign-commands* *:sig* *:sign*