In Total Information Processing Systems v Daman [1992] FSR 171, the court was asked to consider what elements in a computer program were capable of being protected by copyright. Copyright protects an author against copying, but only against the copying of a substantial part of his work. What amounts to 'substantial' varies from context to context, and so provides a happy feeding ground for lawyers.

Here, it was clear, or became clear, that the defendant had copied various elements of the plaintiff's software. Having become clear, the issue was then whether what had been copied was so substantial a part of the plaintiff's work, that the plaintiff should be given damages.

Three separate categories of work came under the judge's inspection:-

1. Computer Programs tend to be built up from modules, and to derive their structure from the specifics of links between such modules. A comparison was made with authors who brought together in compilations, the works of other authors works. The collective whole, the scheme of such an arrangement, is protected under UK copyright law. The judge held that such linking together of software modules in any particular way was not comparable, and was not protected by copyright. It was not equivalent to an original literary work, and nor could the compilation as a whole be seen as a separate work on its own.
2. Programmers will know that the correct design of the data structure of an application can make all the difference between a successful implementation, and an entire failure. Given a good data structure, modern applications programs will, almost, program themselves. In this case the judge considered the data directory within a cobol program. The judge in his wisdom found that since such structures did not themselves have any active functionality, they too could not be found to play a sufficiently substantial part, and were therefore not protected by copyright.
3. Last was a more general finding. Copyright protects, as they say, the original expression of an idea. Where, as sometimes will happen with computer programming, there is only one effective way of expressing an idea, that expression, the judge found, was insufficiently original, and was not therefore protectable.

Overall. it was not a good day for the plaintiffs.

I have to say that I found this case depressing. It seems to me that the judge, J Baker, concentrated far too much on the idea that a computer program is composed of mere instructions which control what the computer does. He failed to acknowledge the wide variety of elements which must be created and put together to form part of a copyright protectable whole. The case has been 'disapproved' in the later IBCOS case.