IBM 3742 Reference Manual page 15

Position by Position Representation of Data on the I ndex Track in Any One Sector of Sectors 8-26.
Field Name Position Purpose
44 Reserved
Multivolume 45
A blank in this field indicates a data set is not continued on or from another
indicator
diskette; a C indicates a data set is continued on another diskette; an L
indicates the last diskette on which a continued data set resides. * *
46-72 Reserved
Verify mark
73
This field must contain a V or a blank. V indicates the data set has been
verified.
74 Reserved
End of data
75-79
Identifies the address of the next unused sector.
80 Reserved
**When preparing data for conversion by the 3747, check the IBM 3747 Data Converter Reference Manual,GA21-9153,
for the interpretation of the multivolume byte.
Figure 8 (Part 2 of 2). Data Set Label Layout
IBM Diskette 9