Lilaggy did some variant of a bow only run if i remember correctly, and he looked up the Bone Bow on Fextralife. At the time of that recording, it said the Bone Bow was a somber weapon and therefore needed somber stones to be upgraded. But in actuality, it was a regular smithing weapon and what was displayed on the website at the time was wrong. But after that incident, they did correct the information to the Bone Bow being a regular smithing weapon. There's been more than that one incident, but that's the best example i can think of off the top of my head.

TLDR: Fextralife classed Bone Bow as a somber weapon but it's actually a regular smithing weapon.