Received a civil parking charge notice - is it genuine?

A civil parking charge notice was left on my car door window yesterday. The sign which displayed details of the parking restrictions (which I had never seen before) was mounted eight feet high on a wall, which I found difficult to read. Is this genuine or am I being conned?

Asked on 24 November 2012 by BW, via email

Answered by Honest John
If the car park has gates or barriers this is legal. If it has no gates or barriers then this type of notice has been illegal since 1 January 2012, and any enforcement on the basis it describes would amount to criminal damage and very stiff fines for the operators.
Similar questions
I parked in a private car park today that was behind a shop, now closed. It is not a council car park. I paid £1 for an hour, but was seven mins late. I have since got a parking ticket. What do you think?...
A couple of weeks ago my partner parked at a local retail park, where you can stay for two hours for free. This week she received a parking charge letter showing pictures of her arrival and departure from...
My wife parked in a council operated car park and purchased the appropriate ticket. On returning to the car within the allotted time she found the ticket had fallen off the window. Fortunately no PCN had...