Basically, when you can tell sides in a conflict by what they wear. It doesn't matter the specifics of what they wear, just that one side has a distinctly different dress than the other. This is actually quite common in fiction. One example is wearing a uniform for any military, either in fiction or Real Life (since you need to tell who to stab/shoot at). This also means this trope can be enforced by an actual Dress Code. Other times, it can be cultural dresses or the personal styles of the heroes and villains. A Super-Trope to: Examples of Dress-Coded for Your Convenience include: