Thread:Rappy/@comment-25889130-20141221055418/@comment-957747-20141221210257

It sounds like the first example is a bug. Please send that info to Special:Contact so we can get it looked into.

The second is because MediaWiki does not support all HTML5 tags... and this is done intentionally. Most HTML tags, like, can introduce site vulnerability if in the hands of any user (even anonymous users). To utilize , or other unsupported tags, you'd have to do so either through your JS files or through verbatim.