To request a separate index area, other than an imbedded area as described above, you must use a separate DD statement. The element name is specified as (INDEX). The space and unit designations are as required. Notice that only the first DD statement can have a data definition name. The data set name (dsname) must be the same.

//ddname DD DSNAME=dsname(INDEX),---
//       DD DSNAME=dsname(PRIME),---