In this case, you could argue that if you don't know what CAN is, this tool is useless to you. Not all technical documents detail this kind of basic information. I routinely see tools for some technology that don't explain what that technology is. Maybe this is a bad idea, but if you don't work with widgets, then you probably don't need wiget-tools. CAN is a really big deal. It needs no more introduction than USB or TCP/IP, though maybe it would be a good idea to describe what those do too. The fact that you've never heard of it, doesn't make it some niche thing. I constantly see stuff I've never heard of on hacker news, that someone in another industry would assume "everybody knows about".
