The school's uniform policy is a blazer which is mandatory and a jumper which is optional.
The school says that in hot weather some kids wore their jumper, but refused to wear their blazer because the extra layer made them too hot. Staff would tell them to remove their jumper and put on the blazer. Kids argued and refused to comply. Time was wasted. Kids were punished. Bad feeling all round
So to mitigate against the few kids that broke the rule about wearing the mandory blazer, the school now says that in the summer term no one can wear the jumper. Therefore everyone will be cold enough to wear the blazer
Totally misses the point that teenagers are going to teenage. If you put arbitrary rules in place which they don't understand the point of, or agree with, teenagers are going to push back and rebel. Some more than others, some very much to their own detriment.
Nobody has ever convinced me that anyone will learn anything better if they're wearing a particular blazer during the school day. It's all just about moulding kids to comply with authority and has the unintended but obvious consequence of igniting division between kids and school over a complete non issue.