1. An information transfer system comprising: a data terminal capable of connecting to a network and including code storing means for storing a code which indicates one or more capabilities of said data terminal, and code transfer means for transferring the code stored in said code storing means to the network; and a central facility capable of connecting through the network to a plurality of such data terminals which may differ from each other in their capabilities, said central facility including code assigning means for requesting the data terminal to send it capability data describing the capabilities of the data terminal and for assigning a code to the data terminal based on that capability data whereupon the code may be stored in said code storing means of the data terminal, code receiving means for receiving said code transferred from the data terminal through the network, discrimination means for discriminating the code received by said code receiving means and for detecting the capabilities of the data terminal, information storage means for storing plural pieces of information, each piece of which has substantially the same content, but which pieces differ from each other in format, and information transfer means for selecting at least one piece of such information in one of the formats based on the capabilities of the data terminal and for transferring the selected piece of information to the data terminal in a manner appropriate to the capabilities of the data terminal.