Tags like 12.04 and 13.04 are being used almost every time even if the question isn't version-specific, and even if the tag description explicitly says:
You should only use this tag if your question is hardware or version-specific.
Why is it a problem? Because the StackOverflow platform requires you to enter at least a tag when creating a question. Many times people just insert their Ubuntu version as the only tag.
This makes filtering questions very hard: I read uninteresting question (e.g. questions that should be tagged wine) and miss the interesting ones (e.g. bash).
So, what should we do to discourage the improper use of such tags?