diff --git a/runtime/doc/fold.txt b/runtime/doc/fold.txt
index 274e472..56c3c75 100644
--- a/runtime/doc/fold.txt
+++ b/runtime/doc/fold.txt
@@ -121,6 +121,11 @@
 Try to avoid the "=", "a" and "s" return values, since Vim often has to search
 backwards for a line for which the fold level is defined.  This can be slow.
 
+If the 'foldexpr' expression starts with s: or |<SID>|, then it is replaced
+with the script ID (|local-function|). Example: >
+		set foldexpr=s:MyFoldExpr()
+		set foldexpr=<SID>SomeFoldExpr()
+<
 An example of using "a1" and "s1": For a multi-line C comment, a line
 containing "/*" would return "a1" to start a fold, and a line containing "*/"
 would return "s1" to end the fold after that line: >
@@ -543,6 +548,8 @@
 
 These characters can be changed with the 'fillchars' option.
 
+These characters can be changed with the 'fillchars' option.
+
 Where the fold column is too narrow to display all nested folds, digits are
 shown to indicate the nesting level.