First, when a single sentence is basically all there is to say about a tag in the wiki, there's a reasonably good chance that you're looking at a bad tag. I don't think we could call that a blanket rule, but it is a good guide. I don't see any real value in that particular tag, at least not in the way it's been used.
When you find a tag that looks suspect and has been applied to more than a dozen or so questions, the general procedure is to write a short meta question asking if there's any value in having the tag at all. After that, we can remove it and call it a day, or:
- Blacklist it if it's a horrible tag and likely to repeat
- Make it a synonym of another better tag
If you feel strongly regarding which direction should be taken, please include your thoughts in your meta post. When posting here just type 'tag-' in the tag box, it'll bring up a list of tags we frequently use to talk about tags. Yay, tags!
Now, to attribution, a source of a bit of ongoing contention.
Any time you copy content from an external resource, you should cite that resource. Folks have a habit of copying directly from Wikipedia, or elevator pitches right from a project web site without making the attribution clear, and we need to be careful about that. We moan and groan quite loudly when people copy our content without attribution, after all. A good example of how to do it right is:
From the project web site:
Yoyoflux is a flux capacitor implemented entirely in software and
released in source, library and executable formats. Using it, you can
turn any compatible processor into a time machine to explore the
distant past. Support for leaping into the future is available in the
alpha release candidate tree, but you're cautioned to use this branch
at your own risk.
All this software really does is set your system clock, and you'll
figure that out when you use it, but please don't tell anyone once you
Now, if someone simply paraphrased that in their own words, the direct quote would not be necessary - since it's that contributors original contribution. Additionally, if it's just a single sentence that's been altered, or can only really be said one certain way - it's a judgement call.
What I will say is, if a Wikipedia article exists for a tag, or there's an informational project web site available, linking to it is never going to be bad, so it's a good idea to just do so. The link becomes informational, and no one can complain about it being absent if there is ever a dispute over use or attribution.
Generally, if it feels icky to not have a link - we probably need one. In this particular case? Meh, but it won't hurt anything to have one.