Input only or output only specification - Key = '0021'

DALINOUT specifies that the data set is to be processed for input only or output only. In the case of BDAM and BSAM data sets, this key overrides OPEN macro options (INOUT, UPDAT, OUTIN, OUTINX) the same way the JCL LABEL parameter options IN and OUT do. See z/OS MVS JCL Reference for details.

DALINOUT is mutually exclusive with the SYSOUT (DALSYSOU) key. When you code DALINOUT, # and LEN must be one, and PARM contains one of the following values:

X'40': Output only is to be requested.
X'80': Input only is to be requested.

Example:: To specify processing for input only, code

KEY   #     LEN   PARM
0021  0001  0001  80