Enterprise COBOL for z/OS, Version 4.2, Programming Guide

Often the COBOL file status code is too general to pinpoint the disposition of a request.
You can get more detailed information about VSAM input or output requests by coding a second data item in the FILE STATUS clause.

   FILE STATUS IS data-name-1 data-name-8

The data item data-name-1 shown above specifies the COBOL file status key, which you define as a two-character alphanumeric or national data item, or as a two-digit zoned decimal or national decimal item.

The data item data-name-8 specifies the VSAM status code, which you define as a 6-byte alphanumeric group data item that has three subordinate 2-byte binary fields.
The VSAM status code contains meaningful values when the COBOL file status key is not 0.

You can define data-name-8 in the WORKING-STORAGE SECTION, as in VSAM-CODE below.

   01  RETURN-STATUS.
       05 FS-CODE              PIC X(2).
       05 VSAM-CODE.
          10 VSAM-R15-RETURN   PIC S9(4) Usage Comp-5.
          10 VSAM-FUNCTION     PIC S9(4) Usage Comp-5.
          10 VSAM-FEEDBACK     PIC S9(4) Usage Comp-5.

Enterprise COBOL uses data-name-8 to pass information supplied by VSAM.
In the following example, FS-CODE corresponds to data-name-1 and VSAM-CODE corresponds to data-name-8:

Example: checking VSAM status codes