When the ISPF variable
has a length of zero, the value of ISPMISS= is the value that is assigned
to SAS character variables defined to ISPF via the SAS VDEFINE user
exit that have formats or informats associated with them that are
automatically specified. The specified value must be one byte in length.
Note: The
specified value is substituted only if the SAS system option ISPCHARF
is in effect when the variable is identified to ISPF via VDEFINE.
For more information, see
ISPCHARF System Option: z/OS.
To display the current
settings of your ISPF options, use PROC OPTIONS GROUP=ISPF.