When VTAM® processes a formatted Initiate or Terminate request (either received directly from a logical unit or formatted by unformatted system services (USS) from a character-coded logon or logoff), it uses an interpret table to determine which application program is to be notified.
The standard logon command definition should suffice for most networks. See LOGON command for coding details. You will have to write your own interpret table only under special circumstances, for instance, if the logon sequence you want to use does not follow the syntax for USS commands. IBM® does not supply a default table.
See Interpret table for information on coding the macroinstructions that define an interpret table. See z/OS Communications Server: SNA Network Implementation Guide for information about how the table is used.