And since that takes you into the territory of "works" but not "supported" the following may be of some use:
Supported, known to work -> warm fuzzies all around
Supported, not known to not work -> an HPite may be in trouble
Supported, known to not work -> an HPite is in trouble
Unsupported, known to work -> lucky today, unlucky tomorrow?
Unsupported, not known to not work -> there but for the grace of Turing
Unsupported, known to not work -> no, it was not deliberate ;-)