rscs
commented
4 years ago I guess this is a client issue, so maybe it's not needed. My client doesn't show the #channel prefix at the beginning of the message, but others do. Even though it may be duplicative in some cases, I don't think it's a bad thing to specify it in the actual message.
EDIT: The next mIRC release will show the channel name for this numeric, but it still can't hurt to provide the channel in the message in case other clients are broken too.
My client tried to autojoin a bunch of channels before I had identified and I got two generic messages saying, "You need to identify to a registered nick to join that channel." It seems silly not to tell them which channel the error is for, as I had to go hunting to figure it out which channels had failed.