diff --git a/runtime/doc/spell.txt b/runtime/doc/spell.txt
index 3ffd893..e1cc6a5 100644
--- a/runtime/doc/spell.txt
+++ b/runtime/doc/spell.txt
@@ -1058,6 +1058,9 @@
 	SFX F 0 in   [^i]n      # Spion > Spionin  ~
 	SFX F 0 nen  in		# Bauerin > Bauerinnen ~
 
+However, to avoid lots of errors in affix files written for Myspell, you can
+add the IGNOREEXTRA flag.
+
 Apparently Myspell allows an affix name to appear more than once.  Since this
 might also be a mistake, Vim checks for an extra "S".  The affix files for
 Myspell that use this feature apparently have this flag.  Example:
@@ -1111,6 +1114,14 @@
 - CIRCUMFIX, as explained just below.
 
 
+IGNOREEXTRA						*spell-IGNOREEXTRA*
+
+Normally Vim gives an error for an extra field that does not start with '#'.
+This avoids errors going unnoticed.  However, some files created for Myspell
+or Hunspell may contain many entries with an extra field.  Use the IGNOREEXTRA
+flag to avoid lots of errors.
+
+
 CIRCUMFIX						*spell-CIRCUMFIX*
 
 The CIRCUMFIX flag means a prefix and suffix must be added at the same time.
diff --git a/src/spell.c b/src/spell.c
index 5063642..1e52dfb 100644
--- a/src/spell.c
+++ b/src/spell.c
@@ -4841,6 +4841,7 @@
     unsigned	af_nosuggest;	/* NOSUGGEST ID */
     int		af_pfxpostpone;	/* postpone prefixes without chop string and
 				   without flags */
+    int		af_ignoreextra;	/* IGNOREEXTRA present */
     hashtab_T	af_pref;	/* hashtable for prefixes, affheader_T */
     hashtab_T	af_suff;	/* hashtable for suffixes, affheader_T */
     hashtab_T	af_comp;	/* hashtable for compound flags, compitem_T */
@@ -5605,6 +5606,10 @@
 	    {
 		aff->af_pfxpostpone = TRUE;
 	    }
+	    else if (is_aff_rule(items, itemcnt, "IGNOREEXTRA", 1))
+	    {
+		aff->af_ignoreextra = TRUE;
+	    }
 	    else if ((STRCMP(items[0], "PFX") == 0
 					      || STRCMP(items[0], "SFX") == 0)
 		    && aff_todo == 0
@@ -5712,9 +5717,11 @@
 		int		lasti = 5;
 
 		/* Myspell allows extra text after the item, but that might
-		 * mean mistakes go unnoticed.  Require a comment-starter.
-		 * Hunspell uses a "-" item. */
-		if (itemcnt > lasti && *items[lasti] != '#'
+		 * mean mistakes go unnoticed.  Require a comment-starter,
+		 * unless IGNOREEXTRA is used.  Hunspell uses a "-" item. */
+		if (itemcnt > lasti
+			&& !aff->af_ignoreextra
+			&& *items[lasti] != '#'
 			&& (STRCMP(items[lasti], "-") != 0
 						     || itemcnt != lasti + 1))
 		    smsg((char_u *)_(e_afftrailing), fname, lnum, items[lasti]);
diff --git a/src/version.c b/src/version.c
index 53fcc8f..4950539 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    447,
+/**/
     446,
 /**/
     445,