I see, thank you for your explanation.
If I'm getting this right, they've actually stated this in their reply to my informal appeal but cited it as grounds for issuing the ticket because I double parked:
'In any road designated as a restricted street the complete width of the street, from the building line on either side of the street, is included in the restriction. It is therefore a contravention to ‘Double Park’ in any part of the street, whether adjacent to vehicles parked on yellow lines or in any form of parking bay or place.'
I'll post the appeal as above. I'm expecting rejection no matter what I write since it's the same party reviewing it. Then I'm counting on the impartial review at the tribunals to work in my favour.