Like it is done for deprecated attributes (function fixDeprecatedAttributes in Sanitizer.php), deprecated HTML tags should be replaced by CSS, too.
These tags are (see URL):
- big
- center
- font
- strike
- tt
For big, strike and tt this should be easy. font requires the obsolete attributes to be converted to CSS.
I'm not sure, whether it is actually possible to replace center,
<center><table><tr><td>a</td></tr></table></center>
centers the table (tested in Firefox), but something like
<div style="text-align:center; margin-left:auto; margin-right:auto;"><table><tr><td>a</td></tr></table></div>
doesn't.
The changed tags should be given an extra CSS class in order to be able to address them using CSS.
Version: unspecified
Severity: enhancement
URL: http://www.w3.org/TR/2012/WD-html5-diff-20120329/#obsolete-elements
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=40632