Honestly, garb should suffice for an identifier like that. Specific modes of dress to denote social standing and status are pretty normal through history.<br/><br/>Like in Alyssa's case, what she's wearing could be just like a "uniform" of what temple slaves wear. No one else who<em>isn't</em>a slave would wear it (except, perhaps, as some sort of fetish or clever disguise), and if she were to don someone else's outfit, well, now you've got an obvious slave  / serf (being an ungulu, after all) trying to dress above their station.<br/><br/>The way the Romans did it was just to hang a placard on the neck of the slave denoting who they belonged to. And since being some rich person's slave was better than being some absolute nobody foreigner in the tanning district of Rome, it really wasn't an issue.