Was just looking at the suggested edit queue, and saw there are a bunch of edits where someone removed handler from the question.
Instead, I changed most of these to views-handler, as handler is likely too generic. I fat-fingered one and accidentally made views-hander which should probably be deleted. I am not finding any questions using handler, so it can probably be deleted too.
I started to create a tag wiki for this, but I am not sure where to begin with this. Any thoughts on a good description of what views handlers do?