You can define an ACS routine to determine data classes, or end
users can explicitly specify a data class name on the following:
- JCL DD statements
- TSO/E ALLOCATE commands
- Access method services ALLOCATE and DEFINE commands
- Dynamic allocation requests such as through ISPF/PDF data set
allocation panels
End users can explicitly specify data set attributes, and these
specifications take precedence over the data set attributes assigned
through the data class ACS routine.