For example here is a state from GrandPrix.

PKX_CALL_STATE_DETECTED
Description: Incoming call detected and address information is being retrieved (internal state only).

What is meant with "internal state only"?
This means that the state is used internally by GrandPrix and is not visible to the user application (i.e. they won't have a call handle in order to query the state). This state means that an incoming call is present on the channel, but that address information has not yet been fully retrieved. Once the address information is fully retrieved, then an INCOMING_CALL event will be raised and the application will be presented with a call handle.