Comment #6 on issue 1291 by kpreid.switchb.org: Need TameOpaqueElements http://code.google.com/p/google-caja/issues/detail?id=1291
If you try to create one with createElement, you will get a virtualized one, which should have the normal element API, but will have no styling effect.
If one exists in static HTML, it will be rewritten into a real style element located outside the guest HTML, so not accessible.
If one is inserted via innerHTML, I don't know what happens offhand.
