OCLC control number expansion in 2013
If you've built an app that uses OCLC numbers, here's the official "heads up" that they're expanding next year, and you may need to modify your code:
WorldCat continues to grow! 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 eContent 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, and may appear in one or more of these forms in the record:
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
When stored 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.
For more information…See more technical information regarding this change. Also, 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. Questions? Please contact OCLC at firstname.lastname@example.org or 1-800-848-5800 (USA) or 1-614-793-8682.