[Vince]

A return-statement passes control back to the function that called this function in the first place, i.e. "return to where you were before". In this particular case it's the server process. The server process examines the returned result to decide whether to send the "unknown command" message or not (0/1).

I suggest you read the language guide, specifically the section on operators and expressions (starting page 105): https://dl.dropboxusercontent.com/u/.../pawn-lang.pdf