Probably a database/messaging consistency check via human, I wonder what a dropped packet is, back then. E.g. paper jam on the fax machine, "Hey what was that f

Probably a database/messaging consistency check via human, I wonder what a dropped packet is, back then. E.g. paper jam on the fax machine, "Hey what was that fax?" "Dunno, the machine ate it.". I once accompanied a travelling family member to the airport, and the airline didn't have a record of her ticket! This was in the pre-historic times before there was e-tickets, mobile checkin, etc.