The idea is to have a channel where only some users can write on it, like on some IRC channel where only voiced/oped users can talk.

This can be very useful to be able to create an announcement channel with a lot of people.

The only way to achieve this at the moment is to mute every users except the ones you want to be able to talk, which is not practical with a high number of users.

A new type of channel where only moderator can talk should do the trick.