A FlyerTalk Posting Legend
Join Date: Sep 2012
Location: SFO
Programs: AC SE MM, BA Gold, SQ Silver, Bonvoy Tit LTG, Hyatt Glob, HH Diamond
Posts: 44,358
You only need positive space, but you're not going to get rebooked in a higher xlass.
AFAIK, self serve SDC is broken right now.