Hi Matt and thank you for your answer
Just to be sure, by "ad", you mean small banners like those from Google and things like this ? To clarify, by "banner", I mean the main image above the navigation bar (i.e. the one on vBulletin.org :

). We have no external ad on our site.
I saw bits of code with conditions, like this
Quote:
<vb:if condition="$forumid == XX">
|
and so on, but how to adapt it on CMS templates ? And in which template should I put it ?
Thank you !