interesting that "Parkerizing" is also mentioned, which some of us might know as the dull dark (non-reflective) finish that Ka-Bar knives had which provided rust-resistance as well as (maybe) "stealth" for Marine Corps in hand-to-hand combat.
But I digress...from what little i know that (Parkerizing) is basically just the phosphate bath portion of the Bonderizing process, minus any galvanizing zinc, but followed with a baking which maybe allows for a thicker coating than if just dipped and dried(?)