I have only had my carryon bag gate-checked once, last year in Rome on my way to Palermo.
They said it was because the flight was full.
I don’t remember being given any sort of receipt or tag for it, and just got it off the carousel in Palermo.
For those of you who have had a bag gate-checked at the last minute, do you get given a receipt/tag/sticker?
Otherwise, if it’s lost, how would you prove that the airline had possession of it?
The things you think of in the dead of night.