550: `dsname` is a partitioned data set and no member was specified on the `cmd` command.

Explanation

The server attempted to store to a partitioned data set (PDS) but did not provide a member name. cmd is STOR, STOU, or APPE.

System action

The command is rejected. FTP continues.

User response

None.

System programmer response

Provide a member name for the PDS.