Dear Newham,
I apologise if my initial challenge wasn't sufficiently clear but the contravention did not occur as I was entitled to rely on the timeplate for the single yellow line that is on a post near to the line.
The timeplate restricts the yellow line to 7am-7pm Monday to Saturday - as this was a Sunday, the contravention could not have occurred.
I attach a picture of the timeplate.
I also refer you to London Tribunals case 2160040109, in which the adjudicator noted similarly that "the appellant quite reasonably concluded that the yellow line where he was parked was governed by the nearby yellow plate".
I look forward to your early confirmation of cancellation.