I don't understand... Why go through all the trouble of writing a WDL? Why not stick with using normal software licenses (GPL, LGPL, X11, BSD-3clauses,...) for documentation? Anyway, the presence of invariant/opiniated/whatever non-free parts in the body of the *licensed-work* will hardly ever meet the requirement of the DFSG, unless the DFSG is amended.
Just a thought. Etienne -- Etienne M. Gagnon, Ph.D. http://www.info.uqam.ca/~egagnon/ SableVM: http://www.sablevm.org/ SableCC: http://www.sablecc.org/