Since AR Jed felt we should change the name of include/private (and I agree it was appropriate) shouldn't we also change the name of include/finclude?  It has the same problem of  pollution when dumped in a --prefix location.

   Should it be petsc-fortran?  Or petsc-fortran-include?

You can call PETSc from fortran? How quaint! How about include/petsc-quaint?