At the time of check-in, the passenger hands over baggage which is checked by the airport security and sealed. Anything that is above the weight limit or which is not allowed to be carried by the passenger himself to the aircraft cabin is usually handed over to the agent at the time of check-in. The baggage allowance, if any, is prescribed by the airline and anything in excess will warrant additional surcharges.These baggage restrictions are based on the class the passenger is traveling. e.g. Economy Class, First Class, Executive Class.