Some important aspects of the processing of plasma polymerization coating, which are not well known or well practiced, are discussed in a brief topical overview. Those aspects are the following: 1) power input parameters for diffuse luminous gas phase polymerization, DC cathodic polymerization, and low pressure cascade arc torch (LPCAT) polymerization, 2) ionization in negative glow versus molecular dissociation in dissociation glow (cathode glow), 3) influence of the deposition plasma on the substrate polymer, 4) types of plasma polymers, 5) importance of the amorphous nature of plasma polymers, 6) chemical reactions in beams versus in the gas phase, and 7) onion-layered structure of the luminous gas phase and operation scale-up.