<p>What is the way to add a tag in an answer, possibly regarding a tool, approach, or such, but something the original asker did not envision, without editing the asked question?  </p>

<p>I'm presuming the answer to the other question about "should" is "yes" for the following reasons:  </p>

<ul>
<li>There can be multiple valuable and relevant answers to the same
question that approach via different paths where the different
approach would have a different flag.</li>
<li>The asker can't and usually won't know all the relevant tags for the
relevant approaches unless they already know the answer to the
question they are asking, or edit the question after the fact.</li>
<li>Part of the value proposition of CV and SE in general is not the
separation of questions and answers, but their interactions.  It is
often not about one question and one answer. There are great
questions and answers where there are 10 highly useful (and highly
voted) answers to the same question.</li>
<li>Google already goes to the answer that is relevant, so they are
getting a value out of the relationship between question, answer, and
keywords.  Why not build a system that does not require an off-site
google search to find something internal.</li>
</ul>
