RDA Option #3.5: Match AACR2 against RDA if not AACR2, RDA against AACR2, if no RDA This option allows our clients to search an unmatched AACR2 bib heading against RDA (and flip to the RDA version). It also allows our clients to search an unmatched RDA bib heading against AACR2 (and flip to the AACR2 version). Option #3.5 builds off of Option #3 in that it takes an extra step in order to find at least some match if it is available. Please note that Option #3.5 has the potential to flip your headings to one form over the other, depending on that initial matching result in Option #3. Using the same examples from Option #1, we can observe what will happen in Option #3.5. Example #1 You have a bib record with the following fields: bib 245 04 $a The principal’s guide to curriculum leadership. 260 $c 2011, c2011. 700 $a Méndez, Zulma Y. There is no AACR2 authority that exists for this 700 heading. However, there is an RDA authority (created Oct 4, 2010): authority 001 n 2010063506 040 $a DLC $b eng $c DLC $e rda 100 1 $a Méndez, Zulma Y. Your bib heading will match on the 100 field in this RDA authority and so will remain: bib 700 $a Méndez, Zulma Y. Example #2 You have a bib record with the following fields: bib 245 00 $a Glories of the Republic of Tlaxcala, 2011. 700 $a Cuadriello, Jaime. There is an AACR2 authority as well as an RDA authority that exists for this 700 heading (updated on Oct 7, 2010): authority 001 n 00010585 100 1 $a Cuadriello, Jaime. 700 14 $a Cuadriello, Jaime, $d 1956- Your bib heading will match on the 100 field in this AACR2 authority remain: bib 700 $a Cuadriello, Jaime. Even though there are identical AACR2 & RDA authorities for this AACR2 bib heading, our system will first check the AACR2 master authority file for a match. Since it matches on the AACR2 1XX field, there is no need to check against the RDA authority where the 700 14 has been established as the de facto 1XX field. Example #3 You have a bib record with the following fields: bib 040 $e rda 245 00 $a Inside Microsoft Windows 2000. 260 $c 2000. 700 $a Russinovich, Mark E. There is are identical AACR2 & RDA authorities that exist for this 700 heading (updated on Oct 19, 2010): authority 001 n 00010996 100 1 $a Russinovich, Mark E. 700 14 $a Russinovich, Mark E. Your bib heading will match on the 100/700 field in this RDA authority and so will remain: bib 700 $a Russinovich, Mark E. Since the system treats the AACR2 1XX as a 4XX and the RDA 7XX x4 as the new 1XX, either heading can be matched during Option #3.5. Also, since this example bib is listed as an RDA bib, the RDA authority file was checked first. Since both headings are identical, it would have found the match eventually anyway for Option #3.5. Nate Cothran Backstage Library Works