As the site grows larger, we invariably see the same question asked again and again, often with a single, undistinguishable variation.
We have started compiling canonical Q&As and it occurred to me that it would be much easier to locate these if they shared a tag; canonical.
The downside is that, inevitably, questions relating to Ubuntu may get mis-tagged. I think it is worth the risk.
Prompted by this question, and the niggling feeling I had when I first saw it that it had to have been answered before...