After a tough debate between Tim O'Reilly and Q. Todd Dickinson, the director of the U.S. patent office, Peter Murray-Rust suggested that XML-DEV with its permanent archives published on CD-ROM, "could potentially be of value in establishing prior art since 1997-02."

The debate confirmed the distance between the ideas of Open Source developers represented here by O'Reilly and the Patent Office's approach of applying classical legal rules to software inventions often born in the Internet collaborative and open environment - but also highlighted the importance of the US patent "Rule 56" allowing patents to be denied or invalidated because of prior art.

The archives of organized and stable mailing lists may play an increasing role establishing prior art and Murray-Rust sent an invitation to use XML-DEV for this purpose when appropriate :

"Ideas per se are not patentable - it is the expression or implementation of the idea - so records of this would be needed. As 'moderator' I try to take a neutral stand, but if members wish to use XML-DEV to publish in the public domain, please be considerate about volume, relevancy to XML, and value."