Msg#: 4190352 posted 3:15 am on Aug 22, 2010 (gmt 0)
I don't see any reason why the Mayday update would have changed anything here - the dash is still preferable. Concatenation can be ambiguous, and the underscore character is still indexed as a charaacter.
As far as mixing cases - just say no. Either you'll create canonical problems or you'll need to do some very fancy dancing on the server to make sure that only the exact mix of upper and lower case you intend is the one that resolves 200 OK.