You can group sets of file revisions together and tag them to make releases that can be checked out at any time to repeatedly build specific releases of code (a requirement of SCM).

A JSP tag is simply a way of abstracting out code from a JSP file.

Instead of a separate XML file (which can get out of sync with the related code when it changes), assume that you have some Web tag to indicate that a page is an entry for a Webflow.