In an earlier note to these lists, Giles Martin wrote:

>You need different bibliographic records if there are significant
>differences in the hardware or software needed to view/read/use a
>document.  For that reason, you would need separate record for the Word
>and for the WordPerfect versions -- in each case you either need the
>appropriate word-processing program, or a program capable of eading that
>format.    .....

Because slight changes in format can make a big difference in the
usefullness of electronic documents, and because it is so easy to represent
the same "intellectual entity" in different machine-readable formats, the
"multiple versions" problem is really exacerbated for electronic materials.
For this reason, when the electronic location field 856 was defined in
USMARC, we took great care to define the field such that small variations in
format (such as the difference between different word processing program
output, or simple ascii vs. sgml, or different compressions algorithms used)
could be represented in the 856 alone, and not necessitate separate
bibliographic records.  What AACR2 may or may not require is a different
issue.  However, in MARC, if the difference between versions is not great
enough to necessitate a different 008, then you should be able to use a
single bibliographic record with multiple 856 fields for each representation
of the document.

This was very deliberately done by those who worked on defining the 856,
with the understanding that the creation of separate bib records for each
variation in format would be a great disservice to the patrons using our
bibliographic systems.

Priscilla Caplan