diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 3ad65d1..f17cf65 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1,4 +1,4 @@
-*options.txt*	For Vim version 7.0aa.  Last change: 2005 Aug 01
+*options.txt*	For Vim version 7.0aa.  Last change: 2005 Aug 05
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -1607,7 +1607,15 @@
 	with the matching words.  These matches should include the "a:base"
 	text.  When there are no matches return an empty List.
 
+	When searching for matches takes some time call |complete_add()| to
+	add each match to the total list.  These matches should then not
+	appear in the returned list!  Call |complete_check()| now and then to
+	allow the user to press a key while still searching for matches.  Stop
+	searching when it returns non-zero.
+
 	The function must not move the cursor!
+	This option cannot be set from a |modeline| or in the |sandbox|, for
+	security reasons.
 
 	An example that completes the names of the months: >
 		fun! CompleteMonths(findstart, col, base)
@@ -1632,6 +1640,32 @@
 		endfun
 		set completefunc=CompleteMonths
 <
+	The same, but now pretending searching for matches is slow: >
+		fun! CompleteMonths(findstart, col, base)
+		  if a:findstart
+		    " locate the start of the word
+		    let line = getline('.')
+		    let start = a:col
+		    while start > 0 && line[start - 1] =~ '\a'
+		      let start -= 1
+		    endwhile
+		    return start
+		  else
+		    " find months matching with "a:base"
+		    for m in split("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec")
+		      if m =~ '^' . a:base
+			call complete_add(m)
+		      endif
+		      sleep 300m	" simulate searching for next match
+		      if complete_check()
+			break
+		      endif
+		    endfor
+		    return []
+		  endif
+		endfun
+		set completefunc=CompleteMonths
+<
 
 				*'confirm'* *'cf'* *'noconfirm'* *'nocf'*
 'confirm' 'cf'		boolean (default off)