Files
The implementation must supply the application program with the contents of the records and the length of each record. The segment control word (SCW) and the record length word (RLW) are not part of the record.
Labels
The implementation must permit the user to supply enough information to enable him/her to select both the requested files and the volume on which they are recorded.
The implementation must supply the installation with the information contained in the following label fields:
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)
The implementation must supply the application program with the information contained in the following label 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)
The implementation need not supply the user with the information contained in the following label fields:
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)
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 supply the installation with the information recorded in the set of installation volume header labels (UVL), the information contained in the following label fields must be provided:
For each label of a set of installation volume header labels:
reserved for the installation (UVL, positions 5 through 80)
If the implementation is in a position to supply the user with the information recorded in the set of user file header labels (UHL) or user file trailer labels (UTL), the information contained in the following label fields must be supplied:
label number (UHL/UTL, position 4)
reserved for the user (UHL/UTL, positions 5 through 80)