Ironically in Brussels, it's the local schools who are more likely to have school uniforms, the 2 big international schools do not have uniforms at all, a few of the smaller international schools have uniforms.
When BSP visit Brussels for sporting competitions, they do sort of stand out as they are always the only school which turns up in school uniform.
Must say I miss school uniforms, none of our children in 3 different schools have uniforms, though I really wish our eldest's school would at least implement a dress code. Luckily in our children's primaire, there is no pressure like at other primaires to wear Cyrillus or Jacardi etc, the kids very much dress down.
When researching schools, I narrowed the area down so when we came to visiting, I did first visits alone, the ones I liked, I took the children back to. For the eldest, we only had a choice of 2 schools, the youngest ones had an enormous choice, ruled out international ones very quickly, though there was one which stood out as just our sort of school (that was BISB) and visited about half a dozen local ones, making a final choice between 2 schools, we knew immediately though which one we liked best and the head sent us away to "reflechir" and would not let us enrol straightaway.
My colleague worked at a school with PYP, now works at a school with a modified English National curriculum, says PYP is quite a difficult curriculum to get to grips with compared to English NC.