From The Death of Meta Tags:
The reason meta-tags are a problem is that they do not describe the content of the question. They describe some other aspect of the question, like the author’s skill level, or the author’s motivation for asking it, or generally what “kind” of question it is (poll, how-to, etc.).
Meta-tags are actually a subset of a larger problem that I usually call dependent tags. These are tags that don’t say anything by themselves – you can’t tell what the question is about unless they’re paired with some other tag (or several of them). These tags are a problem because people don’t realize this and will often use that as the question’s only tag.
To me, prohibiting best-practices tag appears to be based on, well, on best practices of tag usage at Stack Exchange which, not coincidentally, also appear to be in conformance with more general best practices of Folksonomy.
Think of it.
Wikipedia describes purpose of best practices as follows:
Best practices are used to maintain quality.
As for tagging, point worth paying attention to is made in Wikipedia article on Folksonomy:
Tagging, which is one of the defining characteristics of Web 2.0 services, allows users to collectively classify and find information.
Given above, one can conclude that best practices in tagging Web 2.0 (user-generated) content like at Stack Exchange are those helping to maintain quality of user-generated tags serving the purpose of information classification and retrieval.
wow do I sound high-brow "best practices... are those helping to maintain quality of user-generated tags serving the purpose of information classification and retrieval"
Now, let's look how general considerations above are distilled at respective Stack Exchange FAQ entry:
Section Effective Tags - Bring more attention to your question suggests that
Each tag should stand on its own: if a tag only makes sense when used in a group with other tags, something is wrong. For example, tagging a question as
[studio] (two tags) is wrong.
To start with, best-practices tag can't stand on its own indeed.
For example, if I am interested in best practices on code readability, I would be very disappointed to find content related to best practices of performance optimization.
As you can see, best-practices tag offers no positive value in information classification and retrieval. As such, it becomes a usual suspect for being detrimental to maintaining quality blah blah....
But more than that, this tag is also capable of actively harming the quality of classification.
Imagine a user assigning best-practices tag to the question, expecting it to help in classifying content. Now that the question is tagged, this gives user a false confidence that question is already classified while in fact, it is not.
My ex-colleague who specialized in UX used to call these kind of issues attractive nuisances.
...if (f.e FAQ) clearly states "Meta-tags must not be used alone"... it can be added
Well above leads right to the kind of attractive nuisance issues I mentioned, making it easy for users to do harmful things based on (unrealistic) expectation that they will study instructions.
- Hey you put 380 Volt wire where it is easy to touch.
- So what, we also put a warning sign that it is prohibited to do.