In Britain, we debate the wearing of Muslim headscarves and Sikh bracelets. In South Korea, the concern is with light-coloured, wavy or curly hair.
At many schools, perms and dyes are banned, leaving the student body with uniformly straight, dark hair.
But the small number of children who have naturally wavy or light hair have faced bullying from other pupils and the prospect of being sent home from school by their teachers.
So schools in Seoul have adopted a somewhat drastic solution: they are issuing "natural hair color ID cards" to pupils to confirm that they do indeed have naturally light or curly hair.
It will come as no surprise in Britain - where there are widespread objections to any kind of compulsory ID card - that pupils have expressed alarm at the cards.