@LemonTootski this really simple:
Dear Transport for London,
I challenge liability for this PCN because the alleged contravention did not, and indeed could not occur. The allegation on the notice is "Parked wholly or partly in a suspended bay or space", this contravention only occurs if a vehicle is stationary in a designated parking place or space which has been suspended. As there are no designated parking places on red routes, the contravention alleged did not occur.
Furthermore, Transport for London does not have any authorised sign to convey that a parking place or space has been suspended, no doubt because Transport for London does not provide any designated parking places or spaces, and no such sign is authorised by the Traffic Signs Regulations and General Directions 2016.
Lastly the PCN does not comply with the requirements imposed by the second part of paragraph 3(1)(a) of Schedule 2 to The Civil Enforcement of Road Traffic Contraventions (Approved Devices, Charging Guidelines and General Provisions) (England) Regulations 2022, and that is a procedural impropriety.
It follows that the penalty charge notice must be cancelled.
Yours faithfully,
As with the other case, make sure to keep a screenshot of the confirmation page.