CHANNEL PROPERTY: OPGUARD
Usage: PROP <#channel> OPGUARD [<ON|OFF>]
The OPGUARD property specifies whether a user has to be added to an access list in order to be made operator in the channel. If OPGUARD is set to ON, then you can't set CMODE +o for a user who isn't at least AOP of the channel.
/prop #Philadelphia opguard
/prop #Philadelphia opguard on
See also: CMODE +o and ACCESS