My point is precisely that a GFDL manual *cannot* be incorporated into *ANY* free software project. And this is *different* from the old documentation license, which did not have that problem.
I have never considered the question of whether the GFDL is a free software license. The question seems purely academic, since it is (1) not meant as a license for programs, and (2) clearly an annoying license to use for programs. So I don't know if I would agree this is true. What I can say is that the question has no practical significance. If I have a manual for FOO, I might want to merge it with FOO. Whether that is possible does have practical significance. As I've explained, this cannot be a criterion for whether the manual's license is free, since merging may be forbidden due to incompatibility even with licenses that Debian agrees are free; also, there are other ways to get the job done when merging is impossible. But at least the question is a real question. But if we cannot merge it with FOO, why in the world would we care whether theoretically we could merge it with some other hypothetical program BAR? That question is in meaningful in a theoretical sense, but I don't see a need to ask it. > However, the point is that the simple license, was always compatible > with at least one free software license. For example, one could > easily distribute software under the simple license itself. > > I don't think anyone ever did so. In practice, the issue is not > significant, since you can distribute the manual along with the > software, and make the software access the manual in whichever way you > want. Is that how Emacs gets its doc strings? The text in the manual is usually not suitable for a doc string, and vice versa. I don't copy text from the Emacs manual into a doc string, even though the FSF as copyright holder for both could do so.