"(None)"

I'm one in the "(None)" group too, with a one-liner patch to fix a
regression on a driver. Although I've done it as a paid worker, the kernel
is not what I work with. Just come across that bug when trying to understand
why a piece of hardware we use stopped working.

I don't consider that as paid kernel work, just a one time contribution by
sheer luck.

I'm sure there are lots of people like me in that situation.