PLease don't bloat-quote. It's only an informal representation and I have a judicial review to prepare for, but for now this will do:
Dear London Borough of Richmond upon Thames,
I challenge liability for PCN RT39421829 on the following grounds.
The contravention cannot have occurred because The London Borough of Richmond upon Thames (Waiting and Loading Restriction) (Civil Enforcement Area) (Consolidation No. 8) Order 2008 does not create a waiting restriction at this location. This is because the provisions of the order relevant to this street make reference to a location that does not exist.
Yours faithfully,