I don’t remember reading that you could ask which were supported ahead of time. When I’m interested in that twei details I ask for them one by one all the way thru an enumeration in a loop – it might not be most efficient, but so far I have found it to be pretty quick ~ around 150ms per image to run the Get on each of the 63 standand items (if my enum is right).
..but I guess that doesn’t really answer your question – sorry. If you find the method, post back. And disregard the part of my pm where I said I never got that to work, I found the code and it works – I just don’t gather that info very often.
gabe