title: What does the rc stand for in the names of configuration files?
body: <p>Many tools in the modern JavaScript ecosystem name their configuration files ending in the letters <em>rc</em>. For example:</p>
  <pre><code>ES Lint -&gt; .eslintrc.json
  
  npm -&gt; .npmrc.json
  
  yarn -&gt; .yarnrc
  </code></pre>
  <p>I know that these are configuration files.</p>
  <p>The <strong>c</strong> most likely stands for <em>configuration</em>. What is the <strong>r</strong> in <em>rc</em>?</p>