The GNU Free Documentation License states (Note: the following has been wikified and is unofficial):
The Invariant Sections are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License.
... must be
supplemented by counsels for integrity, bravery and
constancy in the struggle of daily existence to which
the vast mass of mankind, who can not b ...