I did some work on the 4.6.4 branch to add a ScreenNameP parameter switch to acs-subsite. In addition, I defined some sql and tcl functions to allow developers to easily support and honor this switch. I set my patches on to Roberto a while ago, but with the latest changes to registration, etc. they may have to be tweaked to be applied to HEAD. I'm not sure exactly how they may conflict with some of the latest changes.
