They should have mentioned Tyrolian (Austrian) loden, a densely woven and felted wool that is reasonably water-resistant. Since that comes from the weaving, it does not require regular reproofing unlike a waxed cotton trench coat. I have a coat that is the best of both worlds, loden with a Gore-Tex membrane.

I also have a lighter weight Ventile raincoat by Private White VC that is absolutely phenomenal. I wish more brands would adopt it and democratize the fabric.