DALDCBDS specifies that DCB information is to be retrieved from the data set label of a cataloged data set. This data set must reside on a direct access volume and the volume must currently be mounted.
The DSORG, RECFM, OPTCD, BLKSIZE, LRECL, and KEYLEN DCB attributes, and the volume sequence number and expiration date are copied from the data set label. If text units for those parameters are coded in addition to this key, the text unit specifications override the parameters copied from the data set label.
DALDCBDS is mutually exclusive with DCB reference to a ddname (DALDCBDD).
For a given job, the system allows a maximum of 1489 backward references (for a VOL=REF to a dsname or DCB=dsname) when the data set names are 44 characters long. When DALDCBDS is specified, # must be one, LEN is the length of the dsname, and PARM contains the data set name. (A dsname of all blanks is invalid.)
KEY # LEN PARM
002C 0001 0003 C1 C2 C3