When using the "advanced search" feature there is a check box at the bottom for also searching "child forums." Does anyone know what this means? It sounds a little strange considering I was searching the "For Sale" forum. I certainly don't need to buy another one of those...

 

LOL. Their forums within a forum. You could also call them leaf forums or sub-forums. For example, "The Staging Area" has them. In fact they're called sub-forums there -- an odd inconsistency in naming.