We have gotten a few (good, some excellent) questions about multi-reference, multi-configuration, complete active space, and possibly more related terms, recently. I would guess the grand total is around 25 questions relating to that topic. That doesn't sound too much, but it's also not nothing.
The problem here is, that it doesn't really offer great search terms, and quantum-chemistry, computational-chemistry, is quite broad. The use of ab-initio is probably also not the best choice. So I would suggest to cluster those questions in a new tag. (When editing one of those, I really had a hard time finding related questions; and overall that would probably be very helpful for a small, but important field.)
And there comes my problem: I don't really want to decide all by myself how to call it.
Please discuss and decide with me, or tell me it's a stupid idea. Answers are appreciated more than comments.