Thank you for pointing this out.

No. The a tag simply called [tag:controller] is far to vague to be of any use. 
I would interpret it as referring to a controller processor within a circuit board, others seem to interpret it as a games controller. Ambiguity is anathema to tags.

Indeed, the questions with the tag refer to several different types of controller, thus adding confusion rather than clarity.

I will start on rolling back all these edits and would welcome anyone else suggesting such edits.

A more detailed tag or tags, for example [tag:games-controller] may be appropriate.