The following statement is from OCLC's Union List Product Support staff concerning my question about the OCLC Union List User Guide at: http://www.oclc.org/support/documentation/unionlist/using/userguide

        Please refer to the Union List Reference Card, which was updated and expanded to an 8-page format to include everything he needs to know about Z39.71 as it relates to OCLC UL.  We made the decision NOT to update the OCLC Union Listing User Guide in the interest of
time and resources, but to make the reference card comprehensive instead.  Tech Bulletin 243 is now obsolete, with the publication of the updated reference card.

        The Union List Reference Card is available from:
        http://www.oclc.org/support/documentation/pdf/unionlistref.pdf

                and

        http://www.oclc.org/support/documentation/unionlist/using/refcard/default.htm