AIBU to think that if a school has a very strictly enforced and prescriptive school uniform that the staff should have a strict professional dress code too and should not be turning up for work in any of the following: skinny strap tops, tee shirts, flip flops, track suit bottoms, cargo trousers or jeans. And if every child has to wear a collar and tie then so too should every male member of staff. IMO it's called setting an example and showing a little respect for the school community.