What is it with (some) schools and their thoughtlessness this week (see also that thread about kids with sick days being banned from treats) ?
No-one should have to justify their donation - or lack of - with any sort of note. Some parents will forget, others can afford it but can't be bothered, but most who send nothing or less than suggested do so because that's what they can afford. It's wrong to ask for any sort of explanation as people's circumstances are all very different and if you get to the stage where a note's expected, what then happens if the reason given isn't "good enough" ?!
Regardless of children not donating but turning up in expensive gear, can you not consider for a moment that a) such things may have been presents or b) yes, may have been bought by parents, but a while ago when money wasn't so tight, or, even if they don't prioritise spending the "right" way, consider that that's beyond the child's control. If their parents won't give them any money, what can a child do ?
Similarly, not all kids get pocket money - either at all, or on a regular basis. Yet again, this really is a parent issue, not the child's and it's utterly wrong to make snide remarks about being tight - particularly with an audience as other kids quickly pick up on things and can be very cruel. Not that parents should be harangued either - for all the reasons explained above. In this day and age any donations should be gratefully received however much they are but schools also need to understand that "only" £1 may as well be £100 if you literally have no money left at that moment - or need what you have for other things.
Also think it's wrong that kids have to pay not to wear uniform. For those who say don't worry, just wear uniform if you can't pay .... well, it's kind of singling out the "poor" kids isn't it and again, creating a potential for being picked on.
Just can't understand why schools don't think these things through.