<p>It seems that <a href="https://stats.stackexchange.com/posts/312194/revisions">at one point</a> it was supposed to be about the coding of categorical variables.  Note that we now have <a href="https://stats.stackexchange.com/questions/tagged/categorical-encoding" class="post-tag" title="show questions tagged &#39;categorical-encoding&#39;" rel="tag">categorical-encoding</a>.  This tag should just be burninated.  </p>
