<p>At the moment we have a number of possibly relevant tags</p>

<ol>
<li>
<a href="https://stats.stackexchange.com/questions/tagged/leverage" class="post-tag" title="show questions tagged &#39;leverage&#39;" rel="tag">leverage</a> which has 27 entries but no wiki excerpt
</li>
<li>
<a href="https://stats.stackexchange.com/questions/tagged/diagnostic" class="post-tag" title="show questions tagged &#39;diagnostic&#39;" rel="tag">diagnostic</a> which has 162 entries a wiki excerpt but no extended wiki
</li>
<li>
<a href="https://stats.stackexchange.com/questions/tagged/regression-diagnostic" class="post-tag" title="show questions tagged &#39;regression-diagnostic&#39;" rel="tag">regression-diagnostic</a> which is a synonym of <a href="https://stats.stackexchange.com/questions/tagged/diagnostic" class="post-tag" title="show questions tagged &#39;diagnostic&#39;" rel="tag">diagnostic</a>
</li>
<li>
<a href="https://stats.stackexchange.com/questions/tagged/schoenfeld-residuals" class="post-tag" title="show questions tagged &#39;schoenfeld-residuals&#39;" rel="tag">schoenfeld-residuals</a> which has 10 entries and no wiki excerpt
</li>
</ol>

<p>As @Pere remarks we have no tag for Cook's distance.</p>

<p>There are well used tags for <a href="https://stats.stackexchange.com/questions/tagged/residuals" class="post-tag" title="show questions tagged &#39;residuals&#39;" rel="tag">residuals</a> and <a href="https://stats.stackexchange.com/questions/tagged/residual-analysis" class="post-tag" title="show questions tagged &#39;residual-analysis&#39;" rel="tag">residual-analysis</a>.</p>

<p>The simplest solution would be to create the tag for Cook's distance, write wikis for it and leverage and in them suggest the possibility of using <a href="https://stats.stackexchange.com/questions/tagged/diagnostic" class="post-tag" title="show questions tagged &#39;diagnostic&#39;" rel="tag">diagnostic</a> if more than one diagnostic is being considered.</p>

<p>EDIT added 1 March 2017</p>

<p>We now have a tag <a href="https://stats.stackexchange.com/questions/tagged/cooks-distance" class="post-tag" title="show questions tagged &#39;cooks-distance&#39;" rel="tag">cooks-distance</a> with wiki and excerpt and also wiki and excerpt for <a href="https://stats.stackexchange.com/questions/tagged/leverage" class="post-tag" title="show questions tagged &#39;leverage&#39;" rel="tag">leverage</a>. I will tag the ones picked up in the search noted in comments.</p>

<p>Further edit 6 March</p>

<p>I have now gone through all the ones thrown up by @Amoeba's search mentioned in comments and tagged most of them. Some, about one quarter, were not really about Cook, they just mentioned it so I have left them un-tagged.</p>
