What info do I have to provide to this mistaken person?

Location: USA, Virginia, Richmond.

Yesterday someone left a note on my windshield accusing me of running into their car in the parking lot over the weekend. Since I only park there for work, and didn't work over the weekend, they're obviously wrong. Also, I haven't hit anyone in a parking lot ever.
They didn't leave any contact info, so I'm just ignoring it for now, but assuming they leave a future note with contact info or contact me otherwise: What information do I have to give them?
I know if I was in an accident I'd have to give my insurance info, but there's no accident here, so do I still have to give it?
Is there anything I should do at this point that I'm missing?