diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index e28244f..bc7f687 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1909,13 +1909,14 @@
 	insert a space.
 
 					*'commentstring'* *'cms'* *E537*
-'commentstring' 'cms'	string	(default "/*%s*/")
+'commentstring' 'cms'	string	(default "/* %s */")
 			local to buffer
 			{not available when compiled without the |+folding|
 			feature}
 	A template for a comment.  The "%s" in the value is replaced with the
-	comment text.  Currently only used to add markers for folding, see
-	|fold-marker|.  Also used by comment plugins |comment-install|.
+	comment text, and should be padded with a space when possible.
+	Currently used to add markers for folding, see |fold-marker| also
+	commonly used by commenting plugins (e.g. |comment-install|).
 
 			*'compatible'* *'cp'* *'nocompatible'* *'nocp'*
 'compatible' 'cp'	boolean	(default on, off when a |vimrc| or |gvimrc|