IBM 5280 Programmer's Manual page 166

Status Key Return Codes
Indexed Data Set Organization
Table 5: OPEN Status Codes
Status Key COBOL Detected Error
00 No error detected
30
I/O error. See table 7 for additional causes.
92 The file is already opened.
Attempt to open a file after a previous open failed for reasons other than
those given under code 93 below.
File is locked.
ACCESS IS RANDOM, OPEN mode is INPUT or 1-0, and file is
empty.
93 No space available for buffers.
See Table 7 for additional causes.
95 COBOL detected invalid file characteristics:
ASCII not configured in system; file is declared as ASCII.
COBOL record size not equal to record size allocated on diskette by
SYSLABEL.
A delete character was not specified when the data set was allocated.
Data set is multivolume.
Length of index data set records is 4 bytes and ACCESS IS RANDOM;
not allowed. See Chapter 5.
Record length specified for the index data set is not valid. Must be equal
to the length of the record key plus four( 4).
See Table 7 for additional causes.
Appendix B. Status Key Return Codes B- 5