I guess we all carry a bit of the past around in us from earliest days at school, to perhaps going to secondary school, our first real job and so on but perhaps that's a barrier to understanding that today maybe things are different and even perhaps what was normal for even then wasn't necessarily the case for others.
For those of us of a certain age our first school told parents what if any the uniform policy was, some had more a dress code you were expected to keep within in, others a rigid uniform that had to bought and worn OR else!
By high school we saw the prospectus and what it had to say around that and maybe compared notes with mates who perhaps attended a different one to us.
Surprisingly school appeared to have a lot to say about socks, that they should be branded, the length and if they had to have a turn over top.
The bigger thing was colour and most specified grey or for high schools with long trousers, black was common.
On the otherhand girls tended to told they had to be white which somehow got translated into white socks are "girly" and by extension had no business being on any boy and some that still carries on in the world of the adult little boy/schoolboy .