Board Thread:General Discussion/@comment-4347663-20130319235816/@comment-3335785-20130320005610

Some HTML isn't recognised because wiki mark-up is used instead, for instance  or tags. Other HTML is available but has wiki mark-up equivalents, such as &lt;b&gt; or &lt;table&gt;. Other tags such as &lt;br/&gt; don't have any equivalent in wiki mark-up.

We could discuss the pros and cons of this for some time, but ultimately some tags aren't supported, which is generally something MediaWiki, the software Wikia runs on, or rather the Wikimedia Foundation decides upon. You can submit something to Special:Contact/general and ask about adding this, but I wouldn't get you're hopes up. There's usually a reason it's not supported.