Not sure if iabu or not. It's fairly petty but annoyed me.
Last year dd had a straw sun hat for school but running around it came off all the time and didn't sit well over pony tails etc. Anyway, today was very sunny here and dd asked if ssh she could wear a light weight hair band she got last summer from Spain. It's pale pink and basically an elastic hair band that goes over your head but their is extra fabric over the top to protect from the sun - all the kids were wearing them on holiday and they stay on brilliantly. So I let dd wear it as she is very fair haired so I thought it sensible to have protection.
Anyway, she's come home and apparently it's not allowed so she ended up with nothing on her head at play time.
I don't really see why it's a big deal but okay I can accept it's not allowed but I do feel they should have let her wear it today so she was protected. Dd is in year 1 so 6yo.