I'm pretty sure he means a single byte-valued parameter. As you mention a single parameter is not enough to fully describe the polarization but maybe it's good enough - I guess you would average across colors, and say circular polarization would lead to a basically random value.
I did indeed mean a singe, byte-valued parameter indicating angle (similar to the single angle parameter of a mechanical polarizing filter)
Full polarization and phase info would be great to have also but probably not necessary for reflection suppression. And yes purely circular polarization would be undefined in this scenario but again not common (possible?) with reflections.
