User blog comment:Ohmyn0/Making your wiki HTML5 compliant/@comment-3279487-20120706122113/@comment-4674838-20120706172132

From this blog...


 * "Some issues have arisen regarding some HTML code no longer being supported. This is due to MediaWiki 1.19 not supporting certain deprecated and obsolete HTML3 and HTML4 elements."

So, apparently you've discovered that MW 1.19 doesn't have a problem with and in particular. In that case, I'd have to venture that when they'll stop working is impossible to answer at this point.