Star 1/2/3 fares in the "Why?" cabin are booked in M on all carriers, except B for NH and H on AC. (Exceptions apply to OZ & NH domestic flights - book Y).
Starlite/StarSpecial is booked in H on all carriers with the domestic exceptions for NH OZ as well as TG applying.

There is a link to the rules in this forum somewhere - do a search for posts by BlondeBomber. Am sure it's his link & in one of his posts on a Star RTW rules thread.