Field 049 is not part of the standard MARC formats, but is generally used by OCLC libraries for local holdings information.  Typically, it is used to designate locations (holding libraries), copies, and/or volumes of a bibliographic item owned by an OCLC participating institution.

Generally, any field containing a "9" (e.g., 049, 910, etc.) is available for local use, such as local call numbers, holdings, or subject headings.

Field 049 is NOT repeatable.

Check with your system vendor for further information.

See also:

0XX  Numbers and Codes

Variable Data Fields