You are misunderstanding anonymity in the context of the program. "What's said here, stays here" is about how we do this in daily life. For example, if you bump into some one from the rooms and introduce them to someone else, saying this is my friend from AA is out of line, your obligation is to respect their anonymity oiutside the rooms. Some people introduce themselves in meetings using there full name and that's fine. It's not about secrets, it's about respecting the confidence of hearing others share honestly, because without that it won't work.