Remember when we were kids, and they’d introduce us to professions with the little Platonic Member of Said Profession? The doctors in their mint-green scrubs and their hats (often red-crossed), with stethoscopes about their necks and bandages in their hands, the police officers in uniform with badges and whistles?
We remember that. So most of us, when we build our worlds, have the professions in mind, and have the images that come with them. The jeweler carries these tools; the geomancer has those tools. Different guilds and different organizations have different badges, uniforms, dress codes. We know the sumptuary standards—or at the very least, the sumptuary expectations. Heck, some cultures even have clearly visually differentiated varieties of prostitute—and you can tell at one look.
How many of us, though, do this imagery in any sense other than the visual?
Granted, taste probably isn’t on the, well, menu. Who runs around licking people to try to figure out if a con artist tastes different from a priest? (Or, more accurately, how many people can they get away with licking before they’re locked up for their own good?)
Sound is a bit better. You have the professions that require trained voices; one can generally tell the stage actors by their gift for projecting. Some professions really are bad for your vocal cords—drill sergeants, for instance, sound like they have the loudest case of laryngitis the world has ever known. There are those who wear or carry things that will have their own sounds—or be carried by things that have their own sounds, like siren-bearing vehicles, ice cream trucks, or any sort of mount.
Touch is a bit iffier, particularly in worlds that respect the idea of the Personal Space Bubble (handshaking can get away with a lot, though), but it has its uses—physical labor makes for rough skin, the kinds of cloth they can afford to wear (or can get away with wearing) are going to feel different, there’s definitely a difference between accidentally elbowing a person in standard garb and elbowing someone with armor under their clothing.
And then you have smell. We really don’t think about it much, because the world these days is more about fake smells than real ones, and we don’t need to depend on our noses all that much, but for professions that involve a lot of hands-on work, it’s probably going to be the most reliable of the senses. Smells are very good at lingering, after all. And you can get them from a lot of things—the materials a craftsman uses, the animals a farmer or a stablehand might tend (or what’s left of the animals a butcher has come into contact with), the inks on an archivist’s hands, the old paper a librarian tends, the herbs of the medieval healer or the antiseptics of his modern counterpart.
Leave aside vision for a moment. How else does a person in your world tell apart people in different professions, different classes, different groups?