DCCDDNAM specifies the ddnames that are associated with the data sets to be concatenated. When you code DCCDDNAM, # is the number of ddnames being specified, which must be at least 2 and can be up to a maximum of 1635 (X'663'). LEN is the length of the immediately following ddname, up to a maximum of 8, and PARM contains the ddname.
KEY # LEN PARM LEN PARM
0001 0002 0005 D4E8D3C9C2 0006 E2E8E2D3C9C2