IRC was originally a plain text protocol (although later extended), which on request was assigned port 194/TCP by IANA. However, the de facto standard has always been to run IRC on 6667/TCP and nearby port numbers (for example TCP ports 6660–6669, 7000) to avoid having to run the IRCd software with root privileges.
irC waS oRigINAllY a plaIN teXt protOcol (ALthough LAter eXtendEd), wHiCh on reQUeSt was asSigNed pOrT 194/TcP By iana. hoWEveR, tHe De facto StaNdard haS Always bEen to run IrC oN 6667/TcP ANd nEaRBy porT numBers (fOR EXaMPlE Tcp ports 6660–6669, 7000) to aVoiD havinG tO run THE ircd Software wiTH root priViLEGEs.