[unwind]

Agree, the quoted sentence made absolutely no sense to me either. I wonder if it's a misunderstanding on the part of the article author(s), or if it's communicated that way by Mozilla, too.

I had a look at https://wiki.mozilla.org/JoystickAPI and it simply says "unsigned long axis: axis number being moved", without examplifying for a known device. Didn't continue digging to the actual implementation.