**The following guest post is from [John Mark Ockerbloom](http://en.wikipedia.org/wiki/John_Mark_Ockerbloom), library scientist at the [University of Pennsylvania Libraries](http://www.library.upenn.edu/) and editor of [The Online Books Page](http://onlinebooks.library.upenn.edu/). He blogs at [Everybody’s Libraries](http://everybodyslibraries.com/).**
I’ve recently gotten involved with two Open Knowledge Foundation working groups, one on open bibliographic data and one on identifying public domain materials. Folks who follow my Everybody’s Libraries blog have seen me write about the importance of the public domain and open bibliographic records to the future of library services. But it’s also worth noting how the two issues complement each other.
If you want to identify the set of works that are in the public domain in your jurisdiction, for instance, you’ll need to do a lot of bibliographic research. As I describe in a 2007 paper on copyright and provenance, to determine the copyright status of a work you may need to know details about the time and place of first publication, the authors and their lifespans, the copyright notices and registrations associated with a work, and the relationship of the work to other works. Much of this data is included in bibliographic records, or can be more easily located when you have these bibliographic records in hand. And as I’ve described in detail at an ALA presentation, the more open bibliographic data is available, the easier it is for lots of different people (and programs) to analyze it. So promoting open bibliographic data also promotes knowledge of the public domain.
Going the other way, information about the public domain also helps build open bibliographic data. Over the past several years, I’ve been compiling information on copyright registrations and renewals, which in the US are very important for determining public domain status. (As has been noted previously, many books, periodicals, and images from the mid-20th century did not renew their copyrights as required and are now in the public domain in the US.) The catalog of copyright registrations is a US government work, not subject to copyright restrictions. And the catalog itself is a rich source of bibliographic data, with information on book titles, authors, and even publication details. Moreover, this data includes descriptions and identifiers not for specific editions, but for the higher-level FRBR concept of expressions, which can encompass many editions. This higher-level data is increasingly important in the newer, comprehensive catalogs that many groups (ranging from OCLC to the Open Library Project) are now developing. And there’s still more that can be done to get this copyright registration data online, or into forms that can be easily searched and analyzed.
In short, open bibliographic information and copyright information reinforce each other. By joining the Open Knowledge Foundation working groups on these topics, I hope to promote the synergies between them, and between people and groups working on liberating this information. If you’re interested in any of these issues, I hope you get involved as well. More information can be found on the OKFN website.