Initialisation

Directly after the client connected to the server it has to send some information about it's protocol version and the server name (usally the real name of the logged in user). The version number is only one byte long and the length of the following string is already set by the length of the whole package (see above).

[1 BYTE] Client Version             // Version number of the protocol implementation, should be 1 here.
[STRING] Client Name                // The name of the client, probably the user's real name

The same happens in a reverse direction directly after that to tell the client more about the server's version and name:

[1 BYTE] Server Version             // Version number of the protocol implementation, should be 1 here.
[STRING] Server Name                // The name of the server, probably the user's real name