When I read the usage terms for the Open Use Logo, it seems to me that a part of it "may be used to refer to Debian" (and no explicit permission given for ANY other usage) could be interpreted as breaking DFSG 8, "License can't be specific to Debian". If that's a long shot, it's relation to DFSG 6 is not, in my humble and confused opinion. The Open Use Logo only allows it to be used for referring to Debian. Or so it seems. (I'm sorry if the logo license has been discussed in the past, I haven't had time to read all the archives of all Debian lists yet.)
I'm sure Debian has a lot of documents that doesn't pass the DFSG, like the constitution and the social contract (I couldn't see anything on these saying that they were on anything other than copyright). Maybe some policy documents falls under this category, too. I don't see any reason why Debian should strip out parts of GNU manuals that are about their political stance or about "Funding free software" and things like that. Still, I interpret DFSG 3 as if it said "modification of _any_ part of the work must be allowed". I think that this might be an issue that all of Debian should discuss and decide on: To what extent must the DFSG apply to non-program software? The Debian social contract is vague-ish on "what's software" but it can definitely be interpreted as "All of the DFSG must apply to all of the stuff". Would it be a terribly bad idea to bring this up for like, a Debian vote or so? I'm kinda thinking along the lines right now of amending/clarifying DFSG 3, so it says something like: "The license must allow modifications (and derived works) of all parts of the software, with the possible exception of the following non-technical, non-functional, non-program parts: [insert entire list of exceptions here]. The license must allow them to be distributed under the same terms as the license of the original software." I think that the list of exceptions needs to include license texts. Sure, it might be useful to change the GPL so it better fits your organization, but that's annoying. (I hate license proliferation, it's like everyone wants to be the new RMS now. [But who can blame them?]) The list of exception could include philosophical statements and historical accounts, as well. Maybe a few more things (names of authors? copyright notices?). As few things on the list as possible. Artsy things like xfig-examples, images, movies and sounds can live in non-free unless they're modifiable. Okay, that looked ugly, but I hope the generally idea gets across. I mean, if someone packages up sound-effects or something for a game and don't want them changed, of course we can stick that in non-free. That's not a big issue. But if someone puts in a little note about the "history of this program" in /usr/share/doc/program-name, I think it's generally rude to want to change that. I'm afraid this might be terribly insulting. (And I think it is. I'm kinda hitting myself for even suggesting this.) But I guess we're all trying hard to figure out a solution to this issue. I don't know if the Free Software Guidelines are written in stone. Wishing the best, Sunnanvind. (The totally idealistic thing to do would be to make everything public domain, but Debian *is* a better system for including software made of pragmatists, like the Linux kernel and other GPL:ed software. The GPL stands for pragmatism and postcynism in my book, but I believe that it has helped immensely in furthering the free software movement.)

