Fields 090 and 092 are very often used by institution to store their locally
created LC class number and Dewey class number. It is very common to see
that information there. It was not a safe field.

Picking those fields to store other information was not the best choice.
Something in the 9XX would have been better.

However, if someone has info in 090, they could move it to 050, with a
second indicator of 4. 050 can repeat, so the record could have an 050 with
a second indicator of 0 for LC and another with a second indicator of 4 for
the locally created number.

MarcEdit or MARC::pm may be able to make the change.

Field 001 is used for the bibliographic record number. It can be different
for each institution. An institution receiving a record from OCLC, for
example, will move the current record number to 035 and then place their
number in 001 and their institutional code in 003.

Each bibliographic record can have several items attached to that one
record. For instance, an encyclopedia will only have the one record for the
work but each volume must have their individual barcodes, and other copy
information recorded.

The copy and work information should be kept separate and not confused.

Sincerely,
David Bigwood
bigwood@lpi.usra.edu
Lunar &Planetary Institute
Cataloging news: http://www.catalogablog.blogspot.com