Many thanks for taking the time to clarify some points.

No problem at all. The article has now fallen off the front page, so I'm not sure how many people are still reading this, but you deserve a response.

It's fairly easy to show people the fruits of desktop Linux - pop in just one Ubuntu (or Mepis or whatever) CD and leave an hour later with a machine humming away nicely and in the case of Ubuntu very good online user forums to help with the many questions. The user doesn't know it's all based on Debian and may never know. Debian will be mentioned, but probably not that visibly unless you dig around for it.

That's true, but it's not a problem trademark law can solve. Remember that a trademark only protects a mark (logo or word). We could slap all the acknowledgement requirements we like on our trademark license, but it's still easy to avoid them by simply not using the mark except buried in footnotes, as some derivative distributions do.

What you seem to be after is more like the BSD advertising clause, which the FLOSS community has more or less rejected as a bad idea.

I think the solution lies more in Debian advocates and evangelists spreading the word that these derivatives really are in fact derived from Debian. Trying to promulgate something really heavy-handed will probably fail, as RMS's attempt to get people to call their Linux-kernel-based OSes "GNU/Linux" largely has. It's hard to force people to use a label of your choosing, but you can try to educate the marketplace. The results are more difficult to measure, but that doesn't render the exercise worthless.

I wonder if it would make sense for the Debian website to have a "good neighbors" page that identifies derived distributions that prominently acknowledge their Debian heritage and cultivate a good relationship with us.