Ahhhh Ok yes and then there are electronic ballasts such as Icecap's. All my comments above were in regards to "cap and coil" aka "tar" type ballasts.
If I think I know next to nothing about cap-n-coil ballasts I know even less of electronic ballasts. Those are, I think, fairly specialized and although there are a number of manufacturers who are getting into electronic HID ballasts (Workhorse and Advance are I think working on a 175W version but I don't know if they are out to market yet). I have no idea how electronic ballasts will relate to ANSI designations.
I think you now have the sum total of all my knowledge on the topic!

Maybe Steve can now jump in and add some sanity (phonetic sanity, but sanity nonetheless).
