Figure out where ERR_UNKNOWNERROR (400) came from #66
Description
I have no clue what first defined this numeric or where it came from. It's not in the RFCs, it's not in irc2, unreal, ircu, insp. But it is in the original alien lists. Maybe they defined it but it feels like it would've come with an AustHex or the like tag in the origin column if they did.
Search through the old mailing list archives, see the first time it pops up in there.