When "block unknown calls" is enabled, all unknown calls that are not on contact list will be blocked.
Tap "Block function setting" in "Settings" -> "Call settings".
"Block"here means "the call will be blocked and the phone will not ring".
Enable "Display blocked call notification": A notification will appear on status bar when there is an incoming unknown call.
Disable "Display blocked call notification": No notification will appear on status bar when there is an incoming unknown call.
Block unkown SMS (similar to "Block unknown calls")