Another Idea, wich is not so important at the moment:
GSTNet_SendArrayTo(ClientID, .... )
Sending Variables, Arrays and Strings only to a specific client. (currently and a String message can be send)
This way, the server could choose wich gamedata to send to wich client. Especially in a MMORPG, or RPG. The server does not want to send the same data to every client. (for example, data on visible objects for that player)