What are proper status codes for CORS preflight requests?

Question

What status code should a well-written HTTP server return when it gets a CORS preflight (OPTIONS) request?

200, 204 or somethi

Answer 1

I used 204. Now it's not working cross-browser anymore. Use 200. Firefox started rejecting CORS requests if 204 is received in the preflight. It wasted me almost 2 hours debugging it.

Lesson to learn: When in doubt about web standards don't choose what makes sense spec wise(i.e. 204 for no content)...choose what most people do(the easy/stupid choice)