If formal recruitment didn't end the way you hoped, or you're rushing outside the fall formal window entirely, here's the path almost nobody explains clearly upfront.
What COB is. Continuous Open Bidding, an informal recruitment process chapters use to fill open spots any time after formal recruitment ends, sometimes weeks later, sometimes the following semester or year. Chapters that didn't hit their new member quota, or that lose members throughout the year, use COB to fill those spots.
How it's different from formal recruitment. Informal, no set schedule, no matching algorithm, no ranking system. A chapter reaches out directly (sometimes called a "snap bid") if they're interested in you, often based on referrals, involvement on campus, or simply meeting you somewhere organic. There's no simultaneous multi-round structure, it's closer to a normal invitation.
Who ends up going through COB. PNMs who didn't get a bid during formal recruitment, women who decide to rush after freshman year and missed the formal window, transfers arriving mid-year, and sometimes women who dropped formal recruitment and later changed their mind. It carries zero stigma among people who actually understand the system, it's simply a different door into the same house.
How to actually get on a chapter's radar for COB. Follow chapters you're interested in, let your Panhellenic office know you're interested in COB (many keep an interest list), attend any open events chapters host, and don't be shy about reaching out to a member you already know. COB moves on relationships and initiative more than any formal process ever does.
The honest reassurance: plenty of women join through COB and have completely normal, fully-integrated experiences, nobody in the chapter treats a COB new member differently than a formal-recruitment one by the time the semester's over. The door you walked through stops mattering the second you're actually in the room.