This may be a problem (??).  The definition of the outward normal in CGM/DAGMC does not always follow the same convention as a MC code.  Moreover, it may not always be opposite (requiring the reversal indicated here), but may be inconsistent - sometimes aligned, some times reversed.  This may not be possible to resolve!

In DAG-MCNP, this also arises in ambiguous meanings of the cosine bins for F1 tallies.