Sigh. It may still be a decent site, but wow that kind of thing can irk me too!

(For your amusement, one of my favorites: things ending in -ous are likely to be adjectives, while things ending in -us are likely to be nouns. Callus / callous. Mucus (the substance) / mucous (description of a type of tissue, such as a mucous membrane). I once taught a bunch of baby veterinarians this rule.)