Compiler-generated storage areas primarily used to store information
  relating to specific COBOL features.  There are four types: (1) Report
  Writer, (2) Record Management, (3) Database Management, and (4) X/Open
  related.

1  –  1 DB-CONDITION

  A database special register whose value indicates either a successful
  condition or an exception condition.

2  –  2 DB-CURRENT-RECORD-ID

  A database special register containing the subschema user ID number
  (UID) of the record type of the current record of the run unit.  It
  contains zero if there is no current record of the run unit.

3  –  3 DB-CURRENT-RECORD-NAME

  A database special register containing the name of the record type of
  the current record of the run unit.  It contains spaces if there is no
  current record of the run unit.

4  –  4 DB-KEY

  A database special register that holds the dbkey of the record accessed
  by the last FETCH, STORE or FIND statement. This special register can
  be used to fine tune storage strategies in the database.

5  –  5 DB-UWA

  A database special register containing the user work area (UWA). The
  UWA is the record delivery area that is used by the DBCS to make data
  items available to your program.

6  –  6 LINAGE-COUNTER

  A special register whose value points to the current position in the
  page body.

7  –  7 LINE-COUNTER

  A Report Writer special register whose value points to the current line
  in the current page.

8  –  8 PAGE-COUNTER

  A Report Writer special register whose value points to the current page
  in a report.

9  –  9 RMS-CURRENT-FILENAME

  A Record Management Services (RMS) exception condition register
  containing the name of the file causing the exception condition.
  This register is implicitly associated with the file most recently
  operated on by an I/O statement.

10  –  10 RMS-CURRENT-STS

  A Record Management Services (RMS) exception condition register. It
  contains the primary RMS status value of an I-O operation. This
  register is implicitly associated with the file most recently
  operated on by an I/O statement. RMS-CURRENT-STV is the secondary
  value.

11  –  11 RMS-CURRENT-STV

  A Record Management Services (RMS) exception condition register. It
  contains the secondary RMS status value of an I-O operation. This
  register  is implicitly associated with the file most recently
  operated on by an I/O statement. RMS-CURRENT-STS is the primary value.

12  –  12 RMS-FILENAME

  A Record Management Services (RMS) exception condition register
  containing the name of the file causing the exception condition.
  At any point in time, this register must be explicitly associated
  with a particular file.

13  –  13 RMS-STS

  A Record Management Services (RMS) exception condition register. It
  contains the primary RMS status value of an I-O operation. At any
  point in time, this register must be explicitly associated with a
  particular file. RMS-STV is the secondary value.

14  –  14 RMS-STV

  A Record Management Services (RMS) exception condition register. It
  contains the secondary RMS status value of an I-O operation. At any
  point in time, this register must be explicitly associated with a
  particular file. RMS-STS is the primary value.

15  –  15 RETURN-CODE

  A special register that may be used to set a return value for a calling
  program or to retreive the value returned from a called program.