The predefined variables that are available to a REXX program in a z/OS shell environment make symbolic references easier and more consistent—for example, when you are specifying a flag or using a stem variable. Instead of coding a numeric value, you can specify the predefined variable that is used to derive that numeric value.

REXX predefined variables lists all the predefined variables alphabetically and shows their numeric value and data type. If a variable is a stem variable, this shows the data type for the stem variable.

You can also use the index of this document as a reference: under the name of each syscall command are grouped the names of the predefined variables associated with it.