Let’s cut to the chase.
The only “parking” offence that attracts an endorsement and penalty points (as far as I can recall) is, as has been mentioned, under Section 22 of the Road Traffic Act 1988, “Leaving vehicles in dangerous positions”. It says this:
“If a person in charge of a vehicle causes or permits the vehicle or a trailer drawn by it to remain at rest on a road in such a position or in such condition or in such circumstances as to involve a danger of injury to other persons using the road, he is guilty of an offence.”
So the bad parking has to involve a “danger of injury” to other road users. A prosecution is certainly most unlikely to succeed for simply parking on a yellow line or on the wrong side of the road. Parking so as to block the pavement might see a success (depending on the circumstances). We need not go into the details, though, because we don’t know enough about them to form a view as to what a court might think (and when issuing a Fixed Penalty Notice, that is what must be considered). I should think this person is simply being issued with standard “parking tickets” which are now decriminalised offences.