informal recruitment

If you are thinking of sororities... COB is usually held in the Spring. Last year was an exception since Panhellenic raised house quotas. I would not anticipate that happening again, especially with Kappa Delta forming. KD might have a fall COB just to get numbers and maybe some of the lower tier houses might if they didn't make quota. COB can be done any time and its very informal, you might not even know a house is doing COB. Usually they invite girls over to the house for dinner, etc... and then extend bids. It isn't something that is done at a specific time or announced like formal recruitment. It is up to each house how they COB.