Wayne Hineman gave me this one day.  This defines the layout of a
standard label tape.  Originally written as a C header file.
 
/* Length of standard OS labels */
#define OS_LABEL_LEN         80
 
/*----------------------------------------------------------------------
* IBM Standard Labels
*
* To conform to OS standard label conventions, these structures will
* be used.  Fields marked with '->' will be checked for some other
* value prior to altering it.  If the field is already in use, the
* original contents are left unchanged.  Fields marked with '>>' will
* be overwritten.  Fields marked with '--' may be examined, but not
* changed.  Any unmarked fields will be set to blanks.
*---------------------------------------------------------------------*/
 
*----  Vol1Label Definition   ----------------------------------------*/
 1.3     labelId                    /* -- Label identifier         */
 4.1     labelNum                   /* -- label number             */
 5.6     volser                     /* -- volume serial number     */
11.1     reserved1                  /*     reserved                */
12.10    VTOCpointer                /*     VTOC pointer            */
22.14    reserved2                  /*     reserved                */
36.2     recTechnique               /* >> recording technique      */
38.4     reserved3                  /*     reserved                */
42.10    ownerName                  /* -- owner name               */
52.29    reserved4                  /*     reserved                */
 
*----  Hdr1Eof1Label Definition   ------------------------------------*/
  eg VMBARS record after VOL1 header.
 1.3     labelId       HDR          /* >> Label identifier         */
 4.1     labelNum      1            /* >> label number             */
 5.17    dsn           VMB.RZ.BASE  /* -> data set identifier      */
22.6     dsSerialNum   DB0035       /*     data set serial number  */
28.4     volSeqNum     0048         /*     volume sequence number  */
32.4     dsSeqNum      0001         /* >> data set sequence number */
36.4     genNum        0002         /*     generation number       */
40.2     versNum       00           /*     version number          */
42.6     createDate     94045       /* -> creation date            */
48.6     expireDate     94165       /* -> expiration date          */
54.1     security      0            /* -> data set security        */
55.6     blockCount    000000       /* -> block count              */
61.13    systemCode    IBMVM370CMS  /* >> system code              */
74.7     reserved                   /*     reserved                */
 
*----  Hdr2Eof2Label Definition   ------------------------------------*/
 1.3     labelId                    /* >> Label identifier         */
 4.1     labelNum                   /* >> label number             */
 5.1     recfm                      /* >> record format            */
 6.5     blockLength                /* >> block length             */
11.5     recordLength               /* >> record length            */
16.1     tapeDensity                /* >> tape density             */
17.1     dsPosition                 /* >> data set position        */
18.17    jobStep                    /*     job/job step            */
35.2     recTechnique               /* >> recording technique      */
37.1     ctlChar                    /* >> control character        */
38.1     reserved1                  /*     reserved                */
39.1     blockAttr                  /* >> block attribute          */
40.8     reserved2                  /* >> reserved (CU serial)     */
48.1     ckptId                     /* >> checkpoint id            */
49.32    reserved3                  /*     reserved                */