Thankfully, Team Tactics has none! At least, as long as anything connecting to the server is a client. However, I have a feeling that on at least one occasion someone has tested the server with Telnet or something and sent random codes to the server. Thankfully the server survived, but I think I need to get the clients to prove themselves in future.
It's not until a server is in the real world that you really know what it's up against.
In the meantime, here's a screenshot.