People who do not know me who use my first name without asking permission. I am in my 70s and would never have dreamed of doing this with an older person when I was younger.
People who ask impertinent personal questions (for example about my income) when I dont at all know them - my standard reply. "I dont mind you asking impertinent personal questions so long as you dont mind my not answering"
Pretty much a conversation stopper.
People who ask for my phone number when I have no possible reason for them to ring me - eg neighbours.