don't think this is common enough case for core. need to make possible in modules.
Not recalling the use case I tagged this democracyinnovations for :-P. Gotta document that sort of thing.
--John Abbe.....Mon Mar 07 18:09:27 -0800 2011
note: this has been done for wikirate.org (in a module)
--Ethan McCutchen.....2013-04-03 19:27:54 +0000
+discussed in support tickets
+relevant user stories