Years ago I worked at "Motown Cafe" here in NYC - a Motown music "theme" restaurant (like Hard Rock Cafe with the "Motown Sound" instead of rock music). It was a great space, but a REALLY horrible place to work - the management/owners were racist incompetent assholes - and some of the clientel were, how can I state this gently, a little on the "uneducated" side.
For all groups over 5 people, the restaurant would automatically charge a 15% gratuity on the check, so the waiters didn't get stiffed (before this policy, one waitress even got tipped with a food stamp!). So at the bottom of the check, there would be an item that stated:
"Gratuity - 15%".........and then the dollar amount.
After the server had dropped the check for a particularly NON-upscale table, he was called back to the table by the "leader" of the party. She stated:
"My bill is wrong! We did NOT order any 'GRANUITY' - and we DEFINITELY didn't order 15 of 'em!!!!!!!"
She had to be told "gratuity" (not graNuity) meant "tip", and it was automatic.