Introduction to tape processing
- IBM standard labels
- Labels that follow standards published by:
- International Organization for Standardization (ISO)
- American National Standards Institute (ANSI)
- Nonstandard labels
- No labels
- The data set labels that precede the data set are called header labels.
- The data set labels that follow the data set are called trailer labels. They are almost identical to the header labels.
- The data set label groups can include standard user labels at your option.
Usually, the formats of ISO and ANSI labels, which are defined by the respective organizations, are similar to the formats of IBM standard labels. Unless otherwise specified, the term standard label, as used in this manual, refers to IBM, ISO, and ANSI standard labels. However, whereas ISO and ANSI labeled tapes are coded in the American National Standard Code for Information Interchange (ASCII), IBM labeled tapes are coded either in the extended binary-coded-decimal interchange code (EBCDIC) or in binary-coded-decimal interchange code (BCDIC).
Nonstandard tape labels can have any format and are processed by routines that the installation provides. Unlabeled tapes contain only data sets and tape marks.
Figure 1 shows the IBM standard, ISO and ANSI standard, nonstandard, and unlabeled tape layouts for a single data set on a single volume. Detailed layouts and variations for each type are illustrated and described in the appropriate sections of this manual.
Tape volumes with standard tape labels may be defined to Resource Access Control Facility (RACF), a component of the SecureWay Security Server for z/OS, by volume serial under the TAPEVOL class of entities. RACF authorization checking is performed for every standard labeled tape if system-wide tape protection has been specified. No protection is specifically extended by the system to nonstandard labeled tapes, but the installation-written nonstandard tape label routines may provide such protection.
![Basic tape layouts](da4m3010.gif)