Are they OK or not for a free software distro in the FSF sense? To my knowledge, it has always been the analysis that RFC's and similar (C standards, POSIX standards, W3C standards, just about any kind of official standard) are not ok for free distros. Because they are "information for practical use" (term from http://www.gnu.org/distros/free-system-distribution-guidelines.html) but they do not typically allow modification, just verbatim redistribution.
John, Donald, anyone, am I wrong? (I hope so.) Which leaves many free software packages (not just distros) in the position of implementing standards which they are not allowed to distribute. Bizarre and unwelcome IMHO, but that seems to be the consequence. karl
