I've read the replies and issues, and I've thought seriously about it, but I really have to come out against putting acknowledgements on the pages themselves. It's /not/ required by the license, it's /not/ what I would expect someone using our text to do, it clutters the page with information that isn't relevant to most users, it gives a sense to users of the text being a "fixed" rather than "dynamic" thing, and it will create a growing problem in the long run.

Crediting sources, in traditional works in traditional media, has always been in ways that didn't disrupt the work itself. Credits appear after movies, on the copyright page of a book, in footnotes or endnotes, the "About" box of a GUI program, etc., where only those interested in the information would see it. If someone wants to use our text from here, I would likewise expect them to mention us wherever they have their own credit statement, probably on a page linked from the article, not on the article itself.

Putting acknowledgements in the articles themselves I fear might also give the wrong impression about our content here: for one thing, it makes the text look like an imported whole, and might discourage people from making sweeping edits. It might also appear to credit the external source with edits that weren't his, even if the language is vague like "some parts based on...". If the credits are put on a separate page where only people who are interested will see them, then ordinary users won't be confused.

But perhaps the most serious problem I see is that works getting copied from one source to another and to another over periods of time may accumulate more credits than actual text. We don't toot our own horn on article pages, and we don't sign edits on the pages, so why should we treat external sources even better? We're here to serve the readers, not the egos of writers who think writing a sentence or two is a major accomplishment forever worthy of credit. Indeed, we are changing the notion of "authorship" itself, and we shouldn't constrain ourselves to policies that fit the old paradigm.

I personally think that the summary comments and talk pages are fine; but I'm also open to the idea of a "Credits" or "Notes" or "About" namespace specifically for such things. These pages might all automatically start with some boilerplate about the dynamic nature of authorship here and point to our policies. I think we can just create and enforce talk-page policies that serve that purpose well, and document that use.

Another possibility I'm open to is a wiki markup specifically for endnotes and credits, that gets rendered in a smaller font at the end of the article or something, and which is preceded by some boilerplate; for example, maybe something like

<credits> Parts of this article were based on FOLDOC... </credits>

Could render a section at the bottom of the page like:

<blockquote class="credits">Content of Wikipedia is dynamic and editable by all users, many of them anonymous. But copyright license terms may require us to give credit to particular authors at times:

Parts of this article were based on FOLDOC... <blockquote>

The stylesheets would render it small, or in faded colors, or even not at all if we chose.