There has always been an issue with this. I remember we used to only like to add ones from the most notable countries so it wasn't a big unsightly list on the movie page, but I think that has softened. I think non-Latin characters are still a no, though?

FWIW relating to Alex's comment, if someone leaves a list when they add a movie, I will add them if I validate it, but really I am less involved with validation now.