ore instead of hyphen */
.error_status {}
</code></pre>

<pre><code class="language-css good">/* Recommended */
.video-id {}
.ads-sample {}
</code></pre>

<h4 id="Prefixes" class="numbered">Prefixes</h4>

<p>Prefix selectors with an application-specific prefix (optional).</p>

<p>In large projects as well as for code that gets embedded in other projects or on
external sites use prefixes (as namespaces) for class names. Use short, unique
identifiers followed by a dash.</p>

<p>Using namespaces helps preventi