It is also known that undesirable stunts limiting freedom, such as Invariant sections, are allowed under the FSF's definition of "free".
FSF do not claim that FDL-covered works are free software, use a particular odd definition of "software" and don't claim to define "free" in general, leading to disputes about those limitations. At least on what they call "free software" it does exactly what it says on the tin, campaigning for the right to use the program, for any purpose.