So what should you do if your browser is not compliant? The obvious answer is to update it. The most recent version from the major manufacturers are compliant. Many are free, too.
We received an irate message from a user who thought that this site implements some esoteric feature that needed a plug-in (such as a Flash presentation). Please note that this site does not use such external extensions; it only uses well-established Internet standards. Since these standards are quite old (at least in the context of information technology), if your browser is not compatible, please update it. If the manufacturer does not provide an update (or the update it provides is incompatible), blame the manufacturer, not this site; also, consider to change product.