Many drivers in MAME are tagged as non-working. In many cases it is obvious why the drivers don't work. In some cases it is subtle. And quite often, other devs can't even really remember why some games don't work. This section of the wiki is an attempt to provide some additional information that can be widely shared about why the games don't work. Hopefully it will answer some of the many questions out there, and might even encourage others to help complete the driver.
Not sure the best way to organize this yet, but we'll try it by manufacturer first and see how that goes: