runtime(doc): Correct allowed characters at :help 'filetype'
closes: #17366
Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index b1f3e15..38eb31d 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -3633,7 +3633,8 @@
one dot may appear.
This option is not copied to another buffer, independent of the 's' or
'S' flag in 'cpoptions'.
- Only alphanumeric characters, '-' and '_' can be used.
+ Only alphanumeric characters, '-' and '_' can be used (and a '.' is
+ allowed as delimiter when combining different filetypes).
*'fillchars'* *'fcs'*
'fillchars' 'fcs' string (default "vert:|,fold:-,eob:~,lastline:@")