Last modified: 2006-09-25 15:56:31 UTC
Please set class="preview" for <body> tag when page rendered as preview.
Usage of this feature:
CSS - styles used only on preview pages
PS: See also bug 6214 with related request
The preview already appears within a <div id="wikiPreview">
wrapper, which should be plenty for marking previews specially.
If something else is required, please give examples.