Looking at CS, DRC_CMD_BANNER exists and code is still here. Yes, it does nothing (I've tried fastly), no idea why. Probably you can use this only for HLTV, or valve has locked something, don't know.
By the way, In CS, DRC_CMD_SHAKE and DRC_CMD_STUFFTEXT are removed.
There are 2 new DRC_ : 14 and 15.
14 : related to spec mode, especially for Free Look (3) as structure :