Yes, you can _use_ DDC freely. If your library is already catalogued, you don't have to pay anyone to keep using the labels on the shelves or the entries in your catalog. If you have a copy of DDC, you can use it to do any cataloging you need. If you have memorized DDC, you don't need a copy of it, and can use the information freely.
What you cannot do is make or share a copy of any significant portion of DDC. Google copied only a few lines of code from Java API, which the court ruled was allowed under the fair use clause of copyright law. The court evaluated the case under what I understand is the standard method for evaluating fair use: nature of the work, purpose and character of the use, the amount used, and the effect of copying on the market or value of the copyrighted work. Similarly, you could copy a few lines of DDC under fair use. But if you want a copy of any significant amount of DDC, you need to pay for it. You cannot share it with other people under fair use. I believe it would fail at least three of the criteria for fair use.
Note: I am not a lawyer, and have only basic knowledge of copyright law.
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From: Code for Libraries <[log in to unmask]> On Behalf Of Jakob Voß
Sent: Wednesday, April 14, 2021 3:07 AM
To: [log in to unmask]
Subject: [CODE4LIB] DDC is like an API specification so it can be used freely
A colleauge of mine just pointed me to a detail of the court decision in the case Google vs. Oracle. The Suppreme Court of the United States ruled that reimplementation of Java API is no copyright violation but allowed at least under fair use:
The opinion of the Court contains a remarkable section on page 6:
"The second, less obvious, function is to reflect the way in which Java’s creators have divided the potential world of different tasks into an actual world, i.e., precisely which set of potentially millions of different tasks we want to have our Java-based computer systems perform and how we want those tasks arranged and grouped. In this sense, the declaring code performs an organizational function. It determines the structure of the task library that Java’s creators have decided to build. To understand this organizational system, think of the Dewey Decimal System that categorizes books into an accessible system or a travel guide that arranges a city’s attractions into different categories"
Following this argument the Dewey Decimal System can be used as free as the Java API. I think that we (library developers) already assumed for specification of data formats, ontologies and data models but it also applies to other kinds of knowledge organization systems (classification schemes, thesauri, gazetteers...) including DDC. By the way if you know systems not covered in BARTOC.org yet, please let the editors know so we will add them!
I doubt that we can share the raw MARC data of DDC with all of its details, but the class hierarchy, notations and headings (without limitation of depth!) can be used freely as far as I understand the court. Or am I missing something?
Jakob Voß <[log in to unmask]>
Verbundzentrale des GBV (VZG) / Common Library Network Platz der Goettinger Sieben 1, 37073 Göttingen, Germany
+49 (0)551 39-31031, http://www.gbv.de/