Tape marks
The tape mark requirements for ISO/ANSI interchange tapes are:
- Each header label group must be followed by a tape mark that indicates the beginning of the data to be processed.
- Each data set must be followed by a tape mark that indicates the beginning of the trailer label group.
- If the data set is the last one on the volume, each trailer label group must be followed by two tape marks. Otherwise, one tape mark is required.
When creating a data set with Version 3 or Version 4 labels, the system routines write the necessary tape marks.