LG G3100 User Manual page 163

The Call barring service prevents your phone from making or
receiving certain category of calls. This function requires the call
barring password. You can view the following submenus.
The barring service of all outgoing calls.
The barring service of all outgoing international calls.
The barring service of all international outgoing calls except home
network.
The barring service of all incoming calls.
The barring service of all incoming calls when abroad.
You can cancel all barring service.
You can change the password for Call Barring Service.
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