"Jeans are forbidden - mother sends child to school in jeans.
Everyone else wears what is acceptable, so they are available - mother calls them rubbish."

The crux in this argument is what is meant by "acceptable". One school I taught at had no uniform, although orange and blue gel hair spikes an many of the adolescents seemed to be acceptable to most of the adolescents; I preferred "not terribly expensive casual", which would have passed for ordinary work attire anywhere if ties weren't required.

In a town where schools require uniforms I'm quite happy for my kids to wear them but I expect the items of clothing to be inexpensive and the standard of workmanship to enable the items to last a couple of active and growing billy lids before showing deterioration. On top of that, with rare exceptions, I have an abiding antagonism to clothing made entirely, or even mostly, of artificial fibres. So my criteria for clothing to be "acceptable" may well be different from my neighbour's.

The schools I have been involved with, as an adult, sort out the variabilities of "acceptability" largely via consultation with the parents and students using the School Council. Because everybody has some ownership in the result compliance is much less of an issue than it was when I was a student who had no say in the ridiculous caps, vaguely useful blazers and deadening colour schemes that were highly favoured in the vast sea of conformity.

At the end of my elder daughter's first year in high school there was a plebiscite to decide between various options for several items of uniform; the results are reasonably fashionable and the only disadvantage was that the plain dark green skirt she'd worn was replaced by an attractive plaid one and couldn't be handed on to my younger daughter. That seems acceptable. I asked them yesterday whether black jeans were "acceptable" (trousers for both boys and girls are required to be black) and they told me that they are except for formal occasions (excursions etc) but aren't acceptable in terms 1 & 4, our summer terms. They prefer wearing skirts.

School Council consultation with the client community would appear to be the go.

Cheers, Rowan