The alphabetic prefix has always seemed more than a bit unnecessary, ostensibly originating from an attempt to give an OCLC number appearing in the 001 field the same layout as an LCCN. Can OCLC assure us that this change to the prefix will be the last? In any case, the statement about how the OCLC number is treated in the 035 field is not accurate: it's quite often copied from the 001 field, with the OCLC's institution code (003 field) prefixed, as appears to be suggested by the MARC documentation. If it's OCLC's opinion that the alphabetic prefix should always be discarded when creating an 035 from an 001, why do we need the prefix in the first place? Gary L. Strawn, Authorities Librarian, etc. Northwestern University Library, 1970 Campus Drive, Evanston IL 60208-2300 e-mail: [log in to unmask] voice: 847/491-2788 fax: 847/491-8306 Forsan et haec olim meminisse iuvabit. BatchCat version: 2007.22.416 From: Program for Cooperative Cataloging [mailto:[log in to unmask]] On Behalf Of Whitacre,Cynthia Sent: Monday, September 10, 2012 5:04 PM To: [log in to unmask] Subject: [PCCLIST] Expansion of the OCLC control number WorldCat continues to grow! As indicated earlier this year, the OCLC Control Number is anticipated to reach one billion after July 1, 2013. At that point, OCLC will increase the length of the OCLC number to accommodate a variable length number string. If you use and/or store OCLC MARC bibliographic records and the OCLC Control Number, you will notice a change after July 1, 2013. You will need to check the systems at your institution that use OCLC MARC bibliographic records and the OCLC number. You may need to implement changes to ensure those systems will be able to successfully handle the longer OCLC number effective July 1, 2013. For example, libraries may be impacted in the following areas: * Cataloging and IT librarians that download OCLC MARC bibliographic records to the library's local system * Resource sharing librarians using third party ILL management programs that store or use the OCLC number for searching * Reference services librarians using WorldCat Local to help a patron locate an item Publishers, vendors and others that partner with OCLC may be impacted as follows: * Integrated Library Service (ILS) vendors that use OCLC MARC bibliographic records to test compatibility with OCLC * Publishers, material suppliers and electronic content providers that use OCLC MARC bibliographic records in their systems * Developers maintaining services that use OCLC Control Numbers Format of the OCLC Number The OCLC Number resides in the MARC 001 field and may also be stored in other fields. The OCLC Number in the 001 field is formatted as follows: OCLC numbers 1 through 99999999: * "ocm" prefix * oclc control number, 8 digits, right justified with leading zeros * A blank space as the last character Example: ocm00012345 OCLC numbers 100000000 to 999999999: * "ocn" prefix * oclc control number, 9 digits Example: ocn123456789 OCLC numbers 1000000000 and higher: * "on" prefix * oclc control number, 10 or more digits Example: on1234567890 or on1234567890123 In the 035 field, the OCLC number is usually stored with the prefix (OCoLC) and without the "ocm", "ocn" or "on" prefixes; for example: (OCoLC)1234567890. When this change takes place The "on" prefix will be used to identify OCLC Numbers that contain ten or more digits. Nine or eight digit OCLC Numbers will continue to use the "ocn" or "ocm" prefix as described above. The update to the OCLC Number is backwards compatible so that previously defined OCLC Numbers will not be impacted. Previously assigned OCLC Numbers will continue to work as before. What action should you take? If you use and/or store OCLC MARC bibliographic records and the OCLC Control Number, you will notice a change after July 1, 2013. You will need to check the systems at your institution that use OCLC MARC bibliographic records and the OCLC number. You may need to implement changes to ensure those systems will be able to successfully handle the longer OCLC number effective July 1, 2013. Sample records OCLC plans to make a file of sample MARC bibliographic records containing the new, expanded numbers available for download on the OCLC Control Number Expansion website<http://www.oclc.org/batchprocessing/number-expansion.htm> (http://www.oclc.org/batchprocessing/number-expansion.htm) before the end of the calendar year 2012. When the file becomes available, announcements will be widely posted in the same places this notice is being posted. Anyone may then download the file for use in testing their systems. For more information Additional technical information regarding this change is available here<http://www.oclc.org/batchprocessing/number-expansion.htm> (http://www.oclc.org/batchprocessing/number-expansion.htm). Please visit the Web<http://www.oclc.org/batchprocessing/controlnumber.htm> (http://www.oclc.org/batchprocessing/controlnumber.htm) to learn how OCLC Control Numbers are created and how OCLC Batchload services give libraries the ability to match, merge, format and synchronize OCLC Control Numbers between their local systems and WorldCat. To see new OCLC Control Numbers when they are assigned, visit Watch WorldCat Grow<http://www.oclc.org/worldcat/newgrow.htm> (http://www.oclc.org/worldcat/newgrow.htm). If you have questions, please contact us at [log in to unmask]<mailto:[log in to unmask]> or 1-800-848-5800 (USA) or 1-614-793-8682.