Channel modes on AustNet: complete reference

Channel modes allow channel operators (ChanOps) to control access, configure security settings, manage participant behavior, and define how a channel functions. Modes are set using the /mode command (e.g., /mode #channel +mode).

1. Access and Membership Modes

Invite-Only (+i):

1. What it does: Restricts entry so that users cannot join the channel unless they have been explicitly invited by a channel operator using /invite.

Key / Password (+k):

1. What it does: Requires users to provide a specific password string when attempting to join the channel.
2. Usage: /mode #channel +k secretword, and users join via /join #channel secretword.

Registered Only (+R):

1. What it does: Blocks unauthenticated users, permitting entry only to accounts that are officially registered and authenticated with NickOP.

2. Communication and Security Modes

Moderated (+m):

1. What it does: Silences standard participants. Only users with voice status (+v), halfop (+h), operator (+o), or higher privileges can send messages to the channel.

No External Messages (+n):

1. What it does: Blocks messages sent from users who are not currently joined in the channel. This prevents outside users from spamming the room via direct /msg #channel commands.

Topic Lock (+t):

1. What it does: Restricts the ability to change the channel topic (/topic) strictly to channel operators. Regular users cannot alter the room description.

Secret (+s) / Private (+p):

1. What it does: Hides the channel from global /list queries and /whois profile listings of its members, protecting group privacy.

SSL/TLS Only (+z):

1. What it does: Restricts channel entry exclusively to users connected via a secure, encrypted SSL/TLS port (such as port 6697), rejecting unencrypted connections.

3. Flood Protection and Limit Modes

User Limit (+l):

1. What it does: Caps the maximum number of simultaneous users allowed in the channel. Once the limit is reached, new users cannot join until someone leaves.
2. Usage: /mode #channel +l 50

Flood Control (+f):

1. What it does: Automatically mitigates text spam and flooding by taking action (such as kicking or muting) against users who send messages faster than a specified threshold.

Ban Exceptions (+e) and Invite Exceptions (+I):

1. What it does: Allows operators to whitelist specific hostmasks so they can bypass active channel bans (+b) or invite-only restrictions (+i).

4. Setting and Removing Modes

Operators can add or remove modes by prefixing them with a plus (+) or minus (-) sign:

1. Adding a mode: /mode #channel +im
2. Removing a mode: /mode #channel -i