I remember seeing that too, and after an extensive search I've come up dry. I hate not knowing what terms to use.
As a side note, I recently etched my Tibetan sword with a tomato slice and am now looking at a really cool grey blade with a bright silver tempered section. This is a handy thing to do, as it lets you see exactly where the temper line is, and you can easily have the whole blade polished back up (if you want) in about three minutes with the aid of some Flitz.