About Lighting when stopped: which statement is WRONG?
Inside a built-up area, sidelights when stopped somewhere dangerous or a nuisance are 'advisable, but not required.'.
If your sidelights are enough to stand still, they're also enough to drive away with, as long as you take it easy.
The requirement explicitly applies 'also to any trailer or caravan,' and 'it does not matter whether it is attached to your car or unhitched.'.
Outside the built-up area, sidelights when stopped are a hard duty, not just advice.
Explanation
trap: standing-still rule applied to driving. Book p.186 - the text explicitly warns: with only your sidelights (and rear light) on, you may not drive. Sidelights are exclusively for standing still; for driving you need dipped beam (or full beam)