I asked that in post #88 of this thread
Mr. Starling, is there a reason to leave MC out from 12/12 pattern? Which house system can be used with 12/12? Thanks in advance.
Whoah! Missed this one entirely. I consider the Ascendant to be the leading point of Apollo's Triangle, with the M.C. and Descendant as different versions of the same thing. The visible sky in any given location is contained within the Horoscopic Interval, bounded by the Asc and Desc. The I.C., though, isn't included as a major Sign-ruler.