Oreilly has a great way of making the <font></font> tag non-functional in cases where the content may contain it (for uncontrollable reasons):
Mind you, this won’t validate properly, but it will disable the usefulness of the tag itself.
Add the following to your CSS definitions
font { color: inherit !important;
background: inherit !important;
font-family: inherit !important;
font-size: inherit !important; }
Recommended ‘simple’ replacement for the tag (when you don’t have time to restructure the entire site) is to use the <span></span> tag with appropriate styles to replace all instances of the <font></font> tag in the markup.
