Sythe calls them Miniranks. You can learn more about Miniranks, as well as trade them like Heads mentioned in the Sythe User Centre. Here's a quick guide.
From the dropdown menu you can see a few options. Minirank manager allows you to view your current miniranks. Minirank directory shows you which Miniranks are trade able and exist.
There is also the option to trade Miniranks. You'll need to find someone with the Minirank you're looking for, and then offer them a price for the minirank