I don't actually know what my technical ranking is vis a vis different groups' definitions. For ICG-type events, I compete in Masters/Open division, unless I am a member of a presentation / costume set designed by my kids.
(The last Worldcon we attended, my kids had recently learned how to sew, it was THEIR entry, and despite being eligible for the Youth/Junior division, they chose to reject it in favor of entering in Novice against adults. And THEN they won both presentation and workmanship awards.
I am SOOO frikken' proud of 'em, frankly, for their decision alone.
In the ICG, most people I know find the concept of "sandbagging" (deliberately competing with high skills at a lower rank to insure a win) to be dishonorable and lame-ass (not to mention it earns one a bad reputation.) OTOH, it brings prestige to compete against a higher level group and "prove yourself", and my kids impressed many long-time ICG Masq. people that night. They even handled a tech screw-up (sound) like pros.