cob

COB technically refers to informal recruitment and stands for Continuous Open Bidding. Basically if a chapter is under total, they may extend a few bids to eligible women they already know or they may hold informal recruitment events.

Is that what you mean or are you referring to a snap bid, which chapters under quota give out before/on Bid Day (don't remember quite when the time cutoff is) to women who dropped from formal recruitment or didn't get a bid.

Either way, they're both fairly uncommon statistically speaking, but both happen every year. Depends which houses you're looking at and how many spots they have. It's not something I would count on, but it's not exactly super-rare either.

Any particular reason you're wondering?