IRC glossary: every term you'll run into

IRC has accumulated three decades of jargon. This glossary covers the terms you will actually meet, alphabetically.

Ban (+b) — a channel mode holding a mask like *!*@host; matching users cannot join. See channel modes.

Bouncer (BNC) — an always-on proxy that keeps you connected and replays missed messages. Full article.

ChanServ — the network service managing channel registration and access lists on networks that have services.

Cloak / vhost — a replacement for your visible hostname, hiding your real address; on some networks a project affiliation badge (@user/developer/...).

CTCP — Client-To-Client Protocol; structured requests between clients, e.g. VERSION or PING. /me actions are CTCP under the hood.

DCC — Direct Client-to-Client; peer-to-peer chat and file transfer negotiated over IRC.

Ghost — your previous connection still online after a crash, holding your nick. Killed with NickServ's REGAIN (or historically GHOST).

G-line / K-line — network-wide and per-server bans placed by staff. Being "k-lined" means the server refuses your connection.

Hostmask — the full identity string nick!user@host, used in bans and access lists.

Ident — a legacy protocol where the server queries your machine for your username; failing it gets you a ~ prefix in your hostmask. Harmless today.

IRCd — IRC daemon, the server software: Ergo, InspIRCd, UnrealIRCd, solanum and friends. See running your own server.

IRCv3 — the ongoing standards effort modernizing the protocol. Full article.

Netsplit — two halves of a network losing their link; everyone on the other side appears to quit at once. Full article.

NickServ — the service that registers nicknames. How to register.

Op (@) — channel operator: can kick, ban, set modes and topic. "Network operator" (oper) is staff of the network itself — a different thing.

SASL — authentication during connection rather than after; the modern way to identify. Covered in the nickname guide.

Services — the persistent bots (NickServ, ChanServ, alis…) providing registration on top of the bare protocol. EFnet and IRCnet famously have none.

Voice (+v) — permission to speak in moderated (+m) channels; shown as a + prefix.

Wallops — network-wide notices from operators, opt-in via user mode +w.

Whois — /whois nick, the command that shows a user's hostmask, channels and idle time.

Missing a term? The commands cheat sheet covers the practical side of most of these.