Files
The records of the files must be passed to the implementation by the application program.
Labels
The installation must transfer the recording information required in each of the label fields listed below to the implementation; otherwise the implementation must supply this information.
For each volume in a volume set:
volume identifier (VOL1, positions 5 through 10)
volume access indicator (VOL1, position 11).
For each file in a file set:
file access indicator (HDR1, position 54)
If the implementation permits the installation to supply the information to be processed in each of the label fields listed below, the implementation must process this information. If the installation does not supply this information, it must be supplied by the implementation.
For each volume in a volume set:
owner identifier (VOL1, positions 38 through 51)
For each file in a file set:
file set identifier (HDR1, positions 22 through 27)
The implementation must permit the application program to supply the information to be processed in each of the label fields listed below. If the application program does not supply this information, the implementation must supply the information for the appropriate fields.
For each file in a file set:
file name (HDR1, positions 5 through 21)
record format (HDR2, position 5)
block length (HDR2, positions 6 through 10)
record length (HDR2, positions 11 through 15)
If the implementation permits the application program to supply the information to be processed in each of the label fields listed below, the implementation must process this information. If the application program does not supply this information, it must be supplied by the implementation.
For each file in a file set:
generation number (HDR1, positions 36 through 39)
version number (HDR1, positions 40 and 41)
For each file section of a file set:
creation date (HDR1, positions 42 through 47)
expiration date (HDR1, positions 48 through 53)
If the implementation is in a position to process a set of installation volume header labels (UVL), the implementation must permit the installation to supply the information to be processed from the label fields listed below. Processing of the corresponding labels is not requested if the installation does not supply the information.
For each label from a set of installation volume header labels recorded on each volume in a volume set:
reserved for the installation (UVL, positions 5 through 80)
If the implementation is in a position to process a set of user file header labels (UHL) or of user file trailer labels (UTL), the implementation must permit the application program to supply the information to be entered in the label fields listed below for a label set. Processing of the corresponding labels is not requested if the application program does not supply the information.
For each label in a set of user file header/trailer labels for a magnetic tape:
label number (UHL/UTL, position 4)
reserved for the user (UHL/UTL, positions 5 through 80)
The implementation can impose the following restrictions on the user with regard to the record length (HDR2, positions 11 through 15).
If the implementation is processing segmented records, it can define a maximum record length. This should not be less than the maximum permissible block length minus the length of the buffer displacement field and the length of the segment control word (SCW).
If the implementation is processing variable-length records, it can define a maximum record length corresponding to the maximum block length minus the length of the buffer displacement field and the length of the record length word (RLW).