I don't really see much value in keeping a branch around after development is complete (or defunct).<p>If the work is complete then merge it (with no-ff if you want to show the merge explicitly).  If it's defunct then delete it.  If you want to keep it around but discourage further development then tag it or come up with a naming convention.<p>That you have the ability to mark branches as closed in mercurial is mainly paper over their odd decision to not allow deletion of branches.