I think Mrrzy may have just given an example of why the BS prefix has problems - different people have different definitions. If you're just talking about music, musicians, musical events, etc, chances are Joe or other thread title editors will swoop in and remove the "BS" from the thread title.

People often don't use the prefixes, and when they do, they don't use them the way other people think they should. I'll vote for anything which will be immediately understandable (and useful) to all, including first-time visitors.

People don't use "BS" because it sounds derogatory. It's fine for someone who doesn't take themself or their topic too seriously. It's meant to be a sort of self-effacement, tongue-in-cheek thing, and some people are easily insulted, and their pride is more important to them that someone else's irritation at accidentally clicking on something they don't want to read. Additionally, there are some non-music topics which are simply too serious for it to be used. I'm sorry, but if something horrible has happened to someone, I can't justify using a "BS" prefix.

The short version:
I'm pretty much with Joe. Prefixes "ADD" and "REQ," and something to designate non-music threads. BS could be replaced by "NON-MUSIC" (long), "NM" - not immediately evident what it is. ???