Aide Memoires
A player has a poor memory, and in order to compensate, puts any cards that are winners on one side of his hand, separated by a slightly larger gap.
Is this allowed?
I know that there are no rules specifying how a hand must be ordered, and also that if it was not allowed, enforcing that would be nigh on impossible. I'm interested in whether this falls foul of law 40B2(d).
I note with interest that although 40B2(d) appears under the heading of Partnership Understandings, is has a much wider scope.
Finally, I was expecting to find a note to the effect that the headings do not form part of the laws, but if it's there I can't find it.

Comments
I think the note about headings not forming part of the laws was removed in the 2017 Laws.
I don't think anything anyone does when sorting their hand would be considered to be an aid to their memory in the sense that it is prohibited.
If you call this a memory aide then surely sorting your hand into suits would also be a memory aide. Not a rabbit hole I'd care to go down. I think that since ordering your hand as you choose is specifically permitted, the general case about memory aides doesn't apply.
I think what is important is how he does it and when he does it.
If he is declarer it doesn't matter either way, but if he is a defender then it matters how he does it. If, after sorting his hand, he selects a number of cards and puts them on one side, he is telling his partner how many winners he has.
The logic for other situations follows, whether he does it before the auction begins, etc.
Let's say I hold the KS. Declarer wins a trick with the AS. I now move my KS to the right side of my hand as it has become a winner. I don't think this is legal as in effect it tells my partner, if they are watching, that I have the KS; though it would also inform declarer. Though you could argue that it is UI and can be treated in the same way as any other UI.
In practice I would say this needs some sensitivity. A player doing this is either a beginner or perhaps suffering from age-related memory loss. In either case, this kind of aide memoire is unlikely to improve their play dramatically as there is more to remember than just which cards are winners. So perhaps the right thing to do in most cases is to remind the person's partner that they must not take account of how their partner re-orders their cards and not to worry too much about it.