Synopsis
The CommentPlugin lets you hide parts of a Wiki page without actually deleting the text. Comments will only be visible in the Wiki markup when editing or viewing the source.
Usage
Simply place the text to be commented out between <?plugin Comment and ?>:
<?plugin Comment !!! A Hidden Section This text will not show up in the generated HTML page, but it is still visible when editing the WikiMarkup. ?>
Author
Martin Geisler 
gimpster@gimpster.com.
Look at the page source for a hidden comment.