LG G5200 User Manual page 184

If you select this, you can send your phone number to the other party.
That is, your phone number will be displayed on receiver's phone.
If you select this, you can't send your phone number.
If this service is Enable, you can accept a waiting (incoming) call. If this
service is Disabled, you cannot recognize the waiting (incoming) call.
Activating the corresponding service.
Deactivating the corresponding service.
Checking the Status of the service.
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