Per Page Area Added Classes Add classes to selected wrapping areas for this page only. Useful for full width layouts – e.g. Parallax. wrapperheader infobarcontainer contentpost footer but I do not know what to do. Where can I read about it.
If what you mean is that you don’t want a sidebar on a specific page, you simply use the page option for that.
On the page Xtreme options for this page, under Sidebar & Widgets, you have a drop down list for “Select Sidebar Layout for this page” Just select “No sidebar content only” in that list