Operator & Server Commands

IRC operators (IRCops) have privileged commands across the network:

C: OPER admin secretpass
S: 381 alice :You are now an IRC operator

Privileges (depend on server config):

• KILL: disconnect user network-wide.
• KLINE: ban hostmask network-wide (k-line).
• GLINE: global k-line.
• CONNECT: link servers.
• SQUIT: disconnect a server.
• WALLOPS: announce to all opers.
• SAJOIN, SAPART: force a user to join/leave.
• SAMODE: bypass mode restrictions.

Standard user commands:

• LIST: list channels.
• WHO: query users by mask.
• WHOIS: detailed user info.
• WHOWAS: history of departed users.
• INVITE: invite to channel.
• KICK: remove user from channel.
• TOPIC: view/set channel topic.

Server commands:

• VERSION: server software.
• TIME: server time.
• INFO: server author.
• ADMIN: server admin contact.
• LUSERS: user counts.
• LINKS: network topology.

Numeric replies (~600 codes, RFC + custom):

• 001-099: reply codes (welcome, info).
• 100-199: server-to-server (rarely seen by client).
• 200-299: stats/info replies.
• 300-399: command-specific replies.
• 400-499: errors.
• 500-599: general errors.

Custom 005 ISUPPORT advertises capabilities:

:server 005 alice CHANTYPES=# CHANMODES=eIb,k,l,imnpst NETWORK=Libera PREFIX=(ov)@+ :are supported

CTCP between users for client identification:

PRIVMSG bob :\x01VERSION\x01
NOTICE alice :\x01VERSION HexChat 2.16\x01

Botnets / spam: IRC was historically the C2 channel for botnets. Network operators implemented:

• Connection throttling.
• Captcha-style proof of human (some networks).
• Heavy logging + analysis.

Modern networks rate-limit every command, ban abusive IPs, integrate spam detection.