At my school, you could figure out pretty easily if you'd gotten a snap bid. You could go to a maximum of 2 pref parties and you were allowed to list only sororities whose pref parties you'd attended on your pref card, and sororities listed only women who attended their pref parties on their bid lists. So if you preffed at A and B and got a bid from C, it was plainly a snap bid. I think rho chi's explained it so the PNM's weren't thinking "where the heck did
this random bid come from..." And since the sorority who offered you the snap bid wasn't listed on your pref card, you were not bound for a year.
Sororities at my school didn't do a lot of snap bidding - we tended to go the COB route - so I may not have my facts 100% straight
