Original sentence: The passenger stub is typically handed to the passenger or attached to the ticket envelope: a) to aid the passenger in identifying their bag among similar bags at the destination baggage carousel; b) as proof -- still requested at a few airports -- that the passenger is not removing someone else's bag from the baggage reclaim hall; c) as a means for the passenger and carrier to identify and trace a specific bag that has gone astray and was not delivered at the destination
Edited sentence: The passenger stub is typically handed to the passenger or attached to the ticket envelope: a) to aid the passenger in identifying their bag among similar bags at the destination baggage carousel; b) as proof—still requested at a few airports—that the passenger is not removing someone else's bag from the baggage reclaim hall; c) as a means for the passenger and carrier to identify and trace a specific bag that has gone astray and was not delivered at the destination