I think you mean "Rejected cabin bag?"

Let's recap...

Gate Check Bag = Preplanned legitimate service items such as strollers, car seats, wheelchairs, etc. that are declared at Checkin and are required for use in the airport terminal concourse but cannot be stored onboard. Left on the bridge/skycheck cart before the flight and picked up at the bridge/skycheck cart on arrival.

Skycheck Bag = For use on the BEH, DH1, DH3, CRJ, and some DH4 flights. Any items that meet carryon baggage requirements and are chosen by the passenger to not be taken onboard but left on the bridge/skycheck cart before the flight and picked up at the bridge/skycheck cart on arrival.

Oversized Cabin Bags = Bags that do not meet carryon baggage requirements but the passenger has managed to get the bag all the way to the gate. The Sales Agent spots the bag and tags it as checked luggage. It is picked up by the customer at the baggage carousel at their final destination. A fee may even be collected gateside by the Agent if the bag means the passenger has exceeded their free checked luggage allowance.

Pretagged COB (CarryOn Bag) = Bags that are tagged by the Sales Agent in advance or during boarding (e.g.: before the bag gets onboard the aircraft) in anticipation of full overhead bins. Bags are left on the bridge during boarding and picked up by the customer at the baggage carousel at their final destination.

Rejected Cabin Bag = Bags that meet carryon baggage restrictions and are taken onboard by the passenger but there is insufficient room to store them onboard. Flight Attendant summons Sales Agent to tag the bag as checked luggage and is picked up by the customer at the baggage carousel at their final destination.