[petsc-dev] ! is only acceptable comment character in PETSc Fortran code

[Barry Smith]

    I found a couple of places with a C in the first column of some PETSc 
Fortran code. This is wrong, you need to ONLY use ! as the comment character in 
Fortran column 1 to make it completely portable.

    Thanks

    Barry

Yes, most compilers accept C, but not all.