I never had a uniform in primary school (lower/middle school?), but I had one in secondary/high school.
You had to wear either navy or black trousers or skirt. If you wore a skirt it had to be at the knee. The boys had to wear black or charcoal trousers, but while I was there they were also deciding to change the rules to include black/charcoal shorts for boys in the summer.
You had to wear a light blue polo shirt with short sleeves (like a T-shirt). You would get told off if it had long sleeves and that kind of shirt was rather hard to find. What a nuisance.
Over the top of that years/grades 7 and 8 had to wear a navy jumper/sweater with the school logo on one side of the chest. Years/grades 9-11 could choose between a navy, maroon or green jumper/sweater.
Everyone had to wear black shoes with either black, navy or white socks underneath. Girls were allowed to wear heels, but if they did the heels had to be chunky ones.
When we did PE we had to wear a green version of the polo shirt and navy jogging bottoms, shorts or a skirt. If you chose to wear a skirt you had to wear green knickers underneath.
I am not surprised all the girls avoided wearing skirts, especially when many of the PE teachers were creepy.
Does it supress individuality?
I don't think a uniform suppresses individuality at all. People still keep their own personalities, interests and beliefs even when they are in uniform. Perhaps it restricts one's
expression of individuality, but I wouldn't say it takes it entirely away.
Does it create a feeling of equality and belonging?
No. I was always ostracised and bullied. Putting me in the same clothes as everyone else didn't magically make everything better. Perhaps for someone who had a good time at school and many friends to support them, but not for somebody who was 'different' and was constantly attacked for it. I think the only way I would have felt equal and as if I belonged with my schoolmates would have been if I were richer, white, not shy, dumber (they hated me for being clever), louder and followed everybody else more often.
Does it prevent cliques?
Not at all. People with similar personalities and interests still drifted towards each other and eventually formed cliques. Uniform definitely didn't make people blind to other students' personalities and so on.
Does it violate personal freedom?
Only in terms of dressing how you wanted to. Even then you could still play around with what was allowed and add your own personal touch.