A record standing for a claim or a task. A ticket exists so nothing depends on someone remembering.
Old French estiquet (a small note affixed to something), from estiquer (to attach, to stick), of Germanic origin; a ticket has always been a small attached record standing in for a claim, so nothing depends on someone remembering.
A record standing for a claim or a task. It exists precisely so that nothing depends on anyone remembering it unaided.