The funny things about the boys rules is that they mostly boil down to "don't let us catch you looking too much like a girl" but also "don't let us catch you looking too much like an adult man, either"
No long hair. But also no facial hair.
No piercings. No visible tattoos. Nothing that might look like a weapon (including combs, heavy shoes, and tshirts with pictures of guns on them).
No eyeliner or hairspray or jewelry. Nothing too punk but also nothing too fruity. Absolutely nothing that might be scary looking. Or drug affiliated. Or queer.
Heaven fucking help you if you look queer. Summer camps hate that.