Servers and clients interacting through mods happens through ServerCmd and ClientCmds.
They work as follows:
Client calls commandToServer('command',arg1,arg2,...);
Server receives this command, and then calls ServerCmdcommand(client,arg1,arg2,...)
Then for the other way around
Server calls commandToClient(client,'command',arg1,arg2,...);
The client receives this command, and then calls ClientCmdcommand(arg1,arg2,...)