There's a group at your school that doesn't have an actual uniform — but somehow they all look the same. The same kind of trainers, the same way of wearing their bag, the same hairstyles, the same brands. Nobody ever announced the rules. But everyone in the group just knows them, and follows them. You've been thinking about trying to get in with them. And you've realised that step one, before you even speak to anyone, is to start dressing the part — to quietly buy and wear the invisible uniform so you look like you belong. You haven't done it yet. But you've caught yourself studying exactly what they wear, like there's a test you have to pass to be allowed in.