Chat commands available are the same as any typical roleplay server: IC, OOC, shouting, talking quietly, et cetera. One difference that you may spot is that the /ame command now shows the label above your own head, so you can see exactly what other players see.
Hints, Command Usage
The chat box has been revolutionised to make your playing experience as easy as possible. Once you hit the T key and begin typing, the server will suggest the most popular commands as you type, as seen below: