Final answer:
The area described between B and C piers associated with additional vehicle rules is most likely the Manoeuvring Area of an airport, which includes taxiways and areas where aircraft taxi, though airport-specific terminology might vary in designations.
Step-by-step explanation:
The area of the apron that is described as a portion between the B and C piers on the west side of the Domestic Terminal Building, having additional vehicle rules due to the absence of vehicle corridors in the horseshoe, is most likely referring to the Manoeuvring Area. The manoeuvring area is typically the part of the airport where aircraft taxi, take off, and land, and it includes taxiways, which could have specific rules regarding vehicles due to safety concerns. However, the description provided does not neatly fit the conventional definitions of these airport areas, which suggests there may be unique terminologies or designations used at different airports. It's vital for personnel and vehicles to adhere to these specific rules to maintain safety and efficiency on the apron.