Specifies a DCB keyword subparameter needed to complete the data control block.

An alphabetic summary of the DCB keyword subparameters follows this parameter description.

You must supply DCB information through the DCB subparameters if your processing program, the data set label, or your language’s defined values do not complete the data control block.

Names a cataloged data set. The system is to copy DCB information from the data set’s label. The data set must reside on a direct access volume, and the volume must be mounted before the job step is executed.

If dsname represents a VSAM data set, and you are allocating a new data set, you must also supply the RECORG parameter. You can specify RECORG explicitly (through the RECORG parameter), or implicitly, through the DATACLAS or LIKE parameters.

A hyphen is a valid character in a catalogued data set name. A data set name that contains a hyphen must be enclosed in apostrophes if it is used as a DCB subparameter.

The dsname cannot contain special characters, except for periods used in qualifying the name. Do not specify a generation data group (GDG) base name, a GDG relative generation member name, or a member name of a non-GDG data set.

If you do not specify the expiration date of the cataloged data set, the system copies it from the data set label. The system also copies the system code.

If you code any DCB subparameters after the dsname, these subparameters override the corresponding subparameters in the data set label. The system copies from the referenced label only those subparameters not specified on the referencing DD statement.

Specify a backward reference to an earlier DD statement. The system is to copy DCB information from the DCB parameter specified on that DD statement. The DCB parameter of the referenced DD statement must contain subparameters, and it cannot name a cataloged data set or refer to another DD statement.

*.ddname specifies the ddname of an earlier DD statement in the same step. *.stepname.ddname specifies the ddname of a DD statement in an earlier step, stepname, in the same job. *.stepname.procstepname.ddname specifies the ddname of a DD statement in a cataloged or in-stream procedure called by an earlier job step. Stepname is the name of the job step that calls the procedure, and procstepname is the name of the procedure step that contains the DD statement.

If you code any DCB subparameters after the reference, these subparameters override the corresponding subparameters on the referenced DD statement. The system copies from the referenced DD statement only those subparameters not specified on the referencing DD statement.

Do not reference a DD * or a DD DATA statement.