diff --git a/runtime/doc/pattern.txt b/runtime/doc/pattern.txt
index 5f47889..e90e388 100644
--- a/runtime/doc/pattern.txt
+++ b/runtime/doc/pattern.txt
@@ -1,4 +1,4 @@
-*pattern.txt*   For Vim version 7.3.  Last change: 2013 May 17
+*pattern.txt*   For Vim version 7.3.  Last change: 2013 May 29
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -698,6 +698,7 @@
 	For speed it's often much better to avoid this multi.  Try using "\zs"
 	instead |/\zs|.  To match the same as the above example:
 		an\_s\+\zsfile
+	At least set a limit for the look-behind, see below.
 
 	"\@<=" and "\@<!" check for matches just before what follows.
 	Theoretically these matches could start anywhere before this position.
@@ -710,6 +711,18 @@
 	Example			matches ~
 	\1\@<=,\([a-z]\+\)	",abc" in "abc,abc"
 
+\@123<=
+	Like "\@<=" but only look back 123 bytes. This avoids trying lots
+	of matches that are known to fail and make executing the pattern very
+	slow.  Example, check if there is a "<" just before "span":
+		/<\@1<=span
+	This will try matching "<" only one byte before "span", which is the
+	only place that works anyway.
+	After crossing a line boundary, the limit is relative to the end of
+	the line.  Thus the characters at the start of the line with the match
+	are not counted (this is just to keep it simple).
+	The number zero is the same as no limit.
+
 							*/\@<!*
 \@<!	Matches with zero width if the preceding atom does NOT match just
 	before what follows.  Thus this matches if there is no position in the
@@ -719,11 +732,16 @@
 	The match with the preceding atom is made to end just before the match
 	with what follows, thus an atom that ends in ".*" will work.
 	Warning: This can be slow (because many positions need to be checked
-	for a match).
+	for a match).  Use a limit if you can, see below.
 	Example			matches ~
 	\(foo\)\@<!bar		any "bar" that's not in "foobar"
 	\(\/\/.*\)\@<!in	"in" which is not after "//"
 
+\@123<!
+	Like "\@<!" but only look back 123 bytes. This avoids trying lots of
+	matches that are known to fail and make executing the pattern very
+	slow.
+
 							*/\@>*
 \@>	Matches the preceding atom like matching a whole pattern. {not in Vi}
 	Like "(?>pattern)" in Perl.
@@ -1193,6 +1211,8 @@
 Thus only the base characters need to match, the composing characters may be
 different and the number of composing characters may differ.  Only relevant
 when 'encoding' is "utf-8".
+Exception: If the pattern starts with one or more composing characters, these
+must match.
 
 When a composing character appears at the start of the pattern of after an
 item that doesn't include the composing character, a match is found at any
@@ -1202,8 +1222,20 @@
 composing character by itself, except that it doesn't matter what comes before
 this.
 
-The order of composing characters matters, even though changing the order
-doesn't change what a character looks like.  This may change in the future.
+The order of composing characters does not matter.  Also, the text may have
+more composing characters than the pattern, it still matches.  But all
+composing characters in the pattern must be found in the text.
+
+Suppose B is a base character and x and y are composing characters:
+	pattern		text		match ~
+	Bxy		Bxy		yes (perfect match)
+	Bxy		Byx		yes (order ignored)
+	Bxy		By		no (x missing)
+	Bxy		Bx		no (y missing)
+	Bx		Bx		yes (perfect mach)
+	Bx		By		no (x missing)
+	Bx		Bxy		yes (extra y ignored)
+	Bx		Byx		yes (extra y ignored)
 
 ==============================================================================
 9. Compare with Perl patterns				*perl-patterns*