> For example, in the case of Ubuntu or Unity (the engine) you can tell what you're looking at, at a glance.

For Ubuntu people often use the codename (including in quite a few UIs, like [1]), something it presumably inherited from Debian, which does the same. I really dislike it, because I usually know which version number I want, but I rarely know which codename I want and always have to look it up on Wikipedia or the like.

[1]: https://packages.ubuntu.com/search?suite=kinetic&searchon=na...