Could be reporting requirements or KYC stuff. It might differentiate how much information to gather on the passenger or put restrictions on where they can sit, like exit rows.
If it’s an airline, it’s likely to allow them to more accurately predict passenger weight. Planes have weight ratings, and need to be sure their loads are distributed appropriately, (like not having everyone in the very back of the plane). Differentiating the tickets will help them flag potential weight problems before boarding even begins.
Could be reporting requirements or KYC stuff. It might differentiate how much information to gather on the passenger or put restrictions on where they can sit, like exit rows.
If it’s an airline, it’s likely to allow them to more accurately predict passenger weight. Planes have weight ratings, and need to be sure their loads are distributed appropriately, (like not having everyone in the very back of the plane). Differentiating the tickets will help them flag potential weight problems before boarding even begins.
Or all of the above. I doubt it’s just for a single use.