Here is a list to help you learn about NationCHAT Channel modes. They change with time, so check back to be sure you are up to date.
Channel modes can only be modified by channel operators, which are those who have a @ next to their nickname.
Channel mode +b (ban)
This bans a specified user/address or users/addresses from the channel. Any user with a host mask matching this address will be denied entry to the channel. If the user is already in the channel and does not have op/voice status, the user will not be able to speak.
Usage: /MODE #channel +b nick!ident@host
Note: When a new NationCHAT fake host is banned (i.e. !@username.users.nationchat.org) that username is banned regardless of the user’s host.
Channel mode +D (Delayed join mode)
Joining users will not be shown until they are opped/voiced, change the topic or speak.
Usage: /MODE #channel +D
Note that hidden users will not be revealed when the mode is cleared. Hidden users can be seen with /NAMES -d #channel.
Channel mode +d (Hidden users present)
This mode is set automatically by a server when channel mode +D is cleared and there are still users hidden in the channel. It can only be set or cleared by the server and is removed automatically when all users become visible.
Hidden users can be seen with /NAMES -d #channel.
Channel mode +i (Invite only)
This prevents users from joining a channel until they are invited by a channel operator or by X (channel services bot).
Usage: /MODE #channel +i
You may invite users by typing /INVITE nickname #channel. Note that inviting a user bypasses possible bans set on him.
Channel mode +k (Key’ed (Passworded) protected)
This mode sets a channel key/password. If set, only users who know the key will be able to join the channel. Note that users in the channel will be able to see the key/password, so do not set this while anyone you do not trust is still present in the channel.
Usage: /MODE #channel +k <key>
To join a channel which has a key set, do /JOIN #channel key. To remove channel mode +k, use /MODE #channel -k key.
Channel mode +l (Limited)
Only allows a certain number of people to join the channel. You can set the maximum number of people who may be in the channel at a time.
Usage: /MODE #channel +l <limit>
Once this number is reached noone else will be able to join and anyone trying to join will receive a message stating that the channel is full.
Channel mode +m (Moderated)
This mode moderates the channel, i.e. prevents users without voice or op status from sending messages to a channel. A user who is neither an op nor voiced would get a “Cannot send to channel” error message from the server if tries to type to the channel.
Usage: /MODE #channel +m
Channel mode +n (No external messages)
This prevents users from externally messaging a channel. The users must be on the channel to message it.
Usage: /MODE #channel +n
Channel mode +o (Channel operator)
Gives operator status to a user on a channel, allowing them to set or remove channel modes, kick/ban users, set the topic when channel mode +t is set and invite users into the channel.
Usage: /MODE #channel +o nickname
Channel mode +O (Opers Only)
Only IRC operators can join the channel. Users trying to join an oper only channel receive following error message: “#channel :Cannot join channel (+O)“.
Note: An /INVITE cannot override this mode and Only IRC operators can set or unset this mode.
Channel mode +p (Private)
This mode denotes a private channel and prevents the users in the channel being viewed externally. The channel also does not appear in a /LIST or /WHOIS, however the topic can be viewed using the /TOPIC command.
Usage: /MODE #channel +p
Note: +p cannot be set at the same time as +s.
Channel mode +R (Registered Channel)
This mode indicates a channel is registered and is a non user setable/changable mode.
Note: Only services may set or unset this +R mode and not channel operators.
Channel mode +r (Registered users only)
This mode only allows users who are logged into X to join the channel (i.e. have a registered username). They will receive the message “Cannot join channel (+r): this channel requires authentication — you can obtain an account from http://services.nationchat.org/live/” when they attempt to join your channel when not registered. Once they have authed they will be able to join the channel normally.
Usage: /MODE #channel +r
If you’re an operator, and you want a non-registered user to join your channel, you can “override” this mode with the /invite command.
Note: +r is a useful mode to set during flood attacks rather than +i (invite only).
Channel mode +s (Secret)
This mode marks the channel as secret and prevents the users in the channel or the topic being viewed externally using /TOPIC. The channel also does not appear in a /LIST or /WHOIS.
Usage: /MODE #channel +s
Note: +s cannot be set at the same time as +p.
Usage: /MODE #channel +t
Channel mode +v (Voice)
Gives voice status to a user on a channel, thus allowing them to speak when the channel is moderated.
Usage: /MODE #channel +v nickname
Note: Only channel operators (people with @ before their nickname) can add or remove voice.
Channel mode +Z (TLS/SSL only)
This mode prevents users from joining your channel unless they are securely connected via SSL/TLS.
Usage: /MODE #channel +Z
Note: This mode cannot be set while non-SSL members are present.
By default, channels are created with the flags +tnR.