LG -G510 User Manual page 162

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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