SUBSYSTEM NAME field (SSID DECP value)

The SUBSYSTEM NAME field specifies the z/OS® subsystem name for Db2.

Acceptable values: 1–4 characters, the first of which must be a letter (A–Z), #, $, or @. Others must be letters A–Z, integers 0–9, #, $, or @.
Default: DSN1
Update: see below
dsnhdecp: SSID

The name is used in member IEFSSNxx of SYS1.PARMLIB.

If you specified a group attachment name in the GROUP ATTACH field on panel DSNTIPK, the SSID DECP value is set to that value.

Updating the parameters: Different sites have different requirements for identifying Db2 to z/OS; as a result, the updates that DSNTIJMV makes to z/OS PARMLIB members might be incomplete. To ensure that the updates are complete, you should edit the z/OS PARMLIB members directly when you install or migrate Db2. This is substantially easier than editing DSNTIJMV.