Positioning after header label 2

Unless user header labels are to be processed, the system reads forward until a tape mark is found. All labels that follow the HDR2 label are checked for proper sequence until the tape is positioned at the first data set record (unless validation checking has been suppressed). This includes the optional HDR3-HDR9 labels.

Note: If the HDR2 label is missing, processing will continue with the assumption that it is not needed. If the JFCB/DCB merge function needs it because of missing data set characteristics, the OPEN will abnormally terminate.