> Regarding copyright ownership of DTD:
>
> Copyright law protects expressions of ideas, not the underlying ideas
> themselves. In many instances, a well-written DTD can only be expressed in
> a particular manner, with allowances made for naming of elements,
> attributes, etc. Therefore, any protection under copyright law would be
> limited, because the scope of copyright protection is proportional to the
> range of expression available to articulate the underlying ideas
> communicated by the DTD. This is called the "merger doctrine" and is well
> known in copyright law, especially with regard to the area of computers.
I beg to differ. The effort involved in the construction of
substantial DTDs such as those from the DocBook or TEI is a least as
much in the articulation of the ideas in the formal schema language of
SGML DTDs as in the original document structure ideas themselves. As
such, I think any unlicensed redistribution of those DTDs would be a
clear and easily prosecuted case of copyright infringement.
In any case, as it stands a DTD is a document, and documents are ipso
facto copyright by their authors. You're certainly correct that if I
made a rational reconstruction of the DocBook or TEI DTD
functionality, I'd be on pretty safe ground, and even if I expanded
all the parameter entity references of e.g. the TEI under a given set
of switch settings, I might be able to get away with redistribution of
the result, although that's MUCH less clear.
The parallel with QuickSort is illuminating. If I redistribute YOUR
awk implementation of QuickSort, with our without relabling some of
the variables, I've violated your copyright. If I code QuickSort
myself in perl, I'm just fine. If I use a2p on your source and
redistribute the results, the lawyers will have a field day.
ht
--
Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
URL: http://www.ltg.ed.ac.uk/~ht/