You can code logon-interpret routines to validate logons and determine the name of the application program that is to receive the logons. The entry point name must match the routine name specified in the APPLID=(ROUTINE,routine name) operand in the LOGCHAR macroinstruction. All logon-interpret routines specified in an interpret table must be assembled and link-edited with that interpret table.
The logon-interpret routine interface allows the routine to supply a network-qualified application name for interpreted logons.
If you want the logon-interpret routine to supply a network-qualified application name, you need to change the interpret routine parameter list. If you do not want the routine to supply a network-qualified name, you do not need to change the routine parameter list. See z/OS Communications Server: SNA Customization for details about coding the interpret routine parameter list.