Data set header labels

The data set header label group consists of IBM standard data set label 1 (HDR1) and IBM standard data set label 2 (HDR2). The HDR1 label contains operating system and device-dependent data that relates to the data set. The HDR2 label is optional on input and contains additional data set characteristics. These labels are used to identify and describe the data set and to protect it from unauthorized use.

These labels are created automatically by the system each time a data set is recorded on tape.