Plain language is promoted by the Plain English Campaign[?], an independent pressure group fighting for public information to be written in common English. The opposite is an unnecessarily complicated formulation, sometimes called gobbledygook.
... Boulanger[?]
Mathilde Carre[?]
Peter Churchill
Jacques-Yves Cousteau
Paul Eluard (poet, communist resistance)
Marie Fourcade[?]
André Gide
André Malraux ...