&SYSDVAL

&SYSDVAL ("DVAL" is for default value) contains one of the following at any given time:

A null value
The input the user entered when returning control to the CLIST after a TERMIN or TERMING statement
The user's response after a READ statement without operands
The value assigned to &SYSDVAL by an assignment statement.

Initially, &SYSDVAL contains a null value. It can also contain a null value, if:

The user does not enter anything but a pre-defined character string or null line after a TERMIN or TERMING statement.
The user does not enter any input after a READ statement without operands.
You assign a null value to &SYSDVAL.

You can also use &SYSDVAL when performing I/O to a data set. You can assign the data to variables by defining SYSDVAL as the file name of the data set and naming the variables on the READVAL statement. For an example of using &SYSDVAL and READVAL in I/O, see Using &SYSDVAL when performing I/O - the PHONE CLIST.