In most systems, all other communications are done through files or pseudo files, known only to the user by their names and not by their internal mechanism. In other words, most intrasystem communication at the user level is by symbolic reference to both devices and process. Let us define a class of syntax elements for use in our proposed extensions to the protocol. The format of is that of the responding host for the current discussion. Future discussions about foreign-user usage of host facilities may result in a standard format for the entire network.
Most systems can identify files by one plus the .
Others, such as the Burroughs B6500 use multifile identifiers where many may be used in the . The second response returns the requested socket number but signifies that the user, device, or process is not currently available for connection. The last response signifies that no such user, device, or process exists. The above extensions to the protocol are intended to enhance user acclimation to network usage. The element of strangeness is subdued and, in fact, for user of the B6500 erased.