It depends on the intention of the note leaver surely?
Someone was parking on half of my mum’s dropped kerb every day. I check in on her nearly every day and it was a right faff trying to get out of her drive. I could never catch the twat so left a note on their windshield saying the next time they do it I’m calling the police. They left my note on the floor (bastards) but did stop the illegal parking.
Another time one of the neighbours left a note on MY windshield because I’d dared to park outside their house. They don’t have a dropped kerb.
So I think my note was fine and the neighbour’s note was twatty.
Another time I was accosted by a woman in Sainsbury’s for parking in P&C bay, I pointed out the blue badge to her and she then hid behind her husband 