Explanation of fields in IEHLIST formatted VTOC listing

Field	Explanation
BLKSIZE	Block size, in bytes, up to 32760 or device maximum. For fixed-length records, block size is set. For variable or undefined-length records, maximum block size is indicated. Format V unblocked records have a block size 4 greater than the LRECL value.
CREATE TIME	Time of creation for the data set. This will be the number of microseconds since midnight in the format hh:mm:ss.mmmmmm where: hh is the hours mm is the minutes ss is the seconds mmmmmm is the number of microseconds
DATA SET NAME	Maximum length 44 bytes.
DATE.CRE	Creation date for the data set, in the Julian form yyyy.ddd, where ddd is the day and yyyy is the year from 1900 to 2155.
DATE.EXP	Expiration date for the data set, in the Julian form yyyy.ddd, where ddd is the day and yyyy is the year from 1900 to 2155.
DATE.REF	Last referenced date for the data set, in the Julian form yyyy.ddd where ddd is the day and yyyy is the year from 1900 to 2155.
DIR.REM	In a partitioned data set in which the last directory block is being used, this value will be the number of bytes consumed in that 256-byte block. If no value appears here, the partitioned data set has not yet reached the last directory block.
DSORG	Data set organization (by access method): DA = Direct (BDAM) PO = Partitioned (BPAM) PS = Physical Sequential (SAM, QSAM, BSAM) The following condition may also appear after any of the above organizations: U = Unmovable (location-dependent).
EATTR	The current EATTR setting for the data set, which specifies whether a data set can have extended attributes (format 8 and 9 DSCBs) and optionally reside in EAS: NS = EATTR has not been specified. The defaults for EAS eligibility should apply. NO = No extended attributes. The data set can not have extended attributes (format 8 and 9 DSCBs) or optionally reside in EAS. This is the default behavior for non-VSAM data sets. OPT = Extended attributes are optional. The data set can have extended attributes (format 8 and 9 DSCBs) and can optionally reside in EAS. This is the default behavior for VSAM data sets.
EXT	Number of extents (sections) the data set has on this volume.
EXTEND	Original secondary allocation quantity if type of space request was bytes, kilobytes or megabytes. Original average block length if type of space request was average block. The actual secondary value is followed by one of the following 2-character identifiers: AV Average block length BY Original secondary quantity in bytes KB Original secondary quantity in kilobytes MB Original secondary quantity in megabytes
EXTENT NO LOW (C-H) HIGH (C-H)	The cylinder and head (track) address of each extent.
FMT 2 OR 3 (C-H-R)/DSCB (C-H-R)	Two addresses are possible here, each pointing to a data set control block (DSCB) in the VTOC. The cylinder-head(track)-record address on the right always appears and points to the DSCB whose partial contents you are now looking at: the Format 1 or 8 DSCB. There may also be a Format 2 or Format 3 DSCB associated with it. The Format 3 address will be present only for data sets that have exceeded three extents, such that a Format 3 DSCB must be used to contain information about the additional extents.
INITIAL ALLOC	Describes the space attribute that was used for allocating all data set extents. RECS = average block size TRKS = Tracks BLKS = Blocks CYLS = Cylinders ABSTR = Absolute tracks (absolute addresses)
JOB	Job name (eight bytes in EBCDIC).
KEYLEN	Byte length (1-255) of the key of the data records in this data set. 0 indicates that no key exists.
LAST BLK PTR (T-R-L)	Points to the last block written in a sequential or partitioned data set or PDSE. The first number (two digits in this example) is the track, relative to the beginning of the data set. The second number is the block, relative to the beginning of the track. The last number is the number of bytes remaining on the track following that block. If the data set is a PDSE, then the field may be blank.
LAST BLK PTR (TTTT-R)	Points to the last block written in an extended format sequential data set. The first number (four bytesbut two bytes in this example) is the track, relative to the beginning of the data set. The second number is the block, relative to the beginning of the track.
LRECL	Logical record length, in bytes, up to 32760 for nonspanned and 32756 for spanned records. For fixed-length records, LRECL is the actual record length. For variable-length records, LRECL is the maximum length permitted by the device. For undefined-length records, LRECL is zero.
MULTICYLINDER UNITS FIRST CYL ADDR	First cylinder address where cylinder-managed space begins on the volume.
MULTICYLINDER UNITS SPACE	The fixed unit of disk space in cylinders that is larger than a cylinder. This is the minimum allocation unit size for cylinder-managed space. Each extent in cylinder-managed space must have its first cylinder number and total size a multiple of this number of cylinders.
NUMBER OF CYLINDERS	Number of cylinders available on the volume.
OPTCD	Option code (as supplied in the DCB used to create the data set). This 1-byte code is given in hexadecimal characters. See the DS1OPTCD field in the DSCB1 data area in z/OS DFSMSdfp Advanced Services.
RECFM	Record format: F = Fixed length V = Variable length D = ASCII variable length (not valid on disk) U = Undefined length. The following options may also be specified: B = Blocked records S = Spanned records T = Track overflow permitted A = ISO/ANSI control characters M = Machine control characters.
SEQNO	Order of this volume relative to the first volume containing the data set. (SEQ NO will be equal to 1, unless this is a multivolume data set.)
SER NO	Serial number of volume containing the data set. Maximum length 6 bytes. (The serial number may vary if the volume has been renamed since the data set was written, but this field should be the same for each format 1 DSCB for the data set.)
SMS.IND	System-managed storage attributes. A = Extended attributes exist for the data set B = Optimal block size selected by DADSM create C = Compressed format E = Extended format H = HFS type of data set I = Data set is a PDSE L = Large format data set R = Data set is reblockable S = SMS-managed data set U = No BCS entry exists for data set ? = One of the following: PDSE and extended format sequential data sets cannot coexist. Both bits are on – one must be turned off. Extended format sequential data set bit must be on when the compressed extended format data set bit is on.
STEP	Step name (eight bytes in EBCDIC).
VENDOR CODE	Vendor identification defined by the vendor in field DS9ATRV1 in the format 9 DSCB. See Vendor fields in DS9ATRV1 in the format 9 DSCB in z/OS DFSMSdfp Advanced Services.
VENDOR DATA	Beginning of variable-length field (up to 15 bytes) containing vendor data defined by the vendor in field DS9ATRV1 in the format 9 DSCB. See Format-9 DSCB in z/OS DFSMSdfp Advanced Services.
2ND ALLOC	Secondary allocation quantity. If zero, the data set is limited to its primary allocated extent; otherwise, it can expand as necessary into many more extents, each of which is this number of blocks, tracks, or cylinders in size. There are various limits.