<p>We have 700+ Q/A referring to basis functions, and a subset <code>radial-basis</code> tag. There appears to be considerable head-scratching as to what a basis function is, so, I made a <a href="https://stats.stackexchange.com/questions/tagged/basis-function" class="post-tag" title="show questions tagged &#39;basis-function&#39;" rel="tag">basis-function</a> tag the following excerpt:</p>

<blockquote>
  <p>A basis function is an element of a set of functions that span a function space. </p>
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<p>The full wiki is:  </p>

<blockquote>
  <p><a href="https://en.wikipedia.org/wiki/Basis_function" rel="nofollow noreferrer">Basis functions</a> are spanning sets of functions. These include sums of sine waves to match any waveform, <a href="https://en.wikipedia.org/wiki/Radial_basis_function#Types" rel="nofollow noreferrer">radial basis functions</a> used for artificial neural networks, <a href="https://en.wikipedia.org/wiki/Basis_(linear_algebra)#Hamel_basis" rel="nofollow noreferrer">basis vectors</a> of a linear algebra, and $\Sigma_0^{n-1} t^i$ to span a polynomial of degree $n-1$. For the latter, $\Sigma t^i$ is called a cardinal or <a href="https://en.wikipedia.org/wiki/Standard_basis" rel="nofollow noreferrer">standard basis</a> because the coefficients of $t^i$ are all 1's.</p>
</blockquote>

<p><strong>What is needed now?</strong> Do I need to put in 100 or so tags onto Q? What do I do about the synonym structure where <code>radial-basis</code> is a subset of <code>basis-function</code>, anything? There are pluses and minuses to doing that, request advice.  </p>
