In the dim past, I worked in the printing industry, and spent much of my time in a pre-press darkroom.
One of the most curious things I discovered while looking up reference material (this was an old book even then), is that George Eastman, and Kodak, have copyrighted the word darkroom, as well as terms describing the materials, and processes involved both in general photography, and the photographic process as it relates to offset printing.
It's always interesting what may once have been intellectual property, but has become public domain regardless of its actual legal status; I kinda doubt they'll take any action against everyone who has ever infringed on their copyright.
WickerNipple has pointed out seeing this term on other companies' chemicals--especially Fugifilm I would think. I have no explanation; but I really did see that term as some sort of intellectual property.
I also used the term PMT--photo-mechanical transfer--which is a copyright, or trademark term, all the time when I was in the industry; everyone I worked with did, too.
Isn't it strange how the proprietary becomes the generic?