The MAG FB Swap has always been pretty informal. There are HAVES, WANTS, FOOD for the potluck threads already posted for those who want to make pre-arranged trades. Those threads will continue to evolve right up until swap day and the rules for them are at the front of each thread. But there will be plenty of plants offered just for the taking. Our motto is either if you don't bring plants, bring chocolate or if you don't have plants now, you will someday and you can pass them on then.
Every few years, we get a few strangers who join us who go a little crazy and take everything they can including plants clearly marked for someone in particular to pick up. Then we talk about more rules for the following year. But we never do it and it never seems to happen twice in a row. We welcome new people because so many of them bring the most interesting plants.
We are a fun bunch and every time the police have shown up at one of our swaps, we've given them plants to take home too. And yes we have had the police show up, mostly because our spring swaps sometimes have gotten kind of big (like the year we had 77 cars and a neighbor paniced at the way a couple of the plants looked.