W3C Validation Error

Hello Rolf,

as I can see, those are properties, which target older browsers and they all have correct vendor prefixes. On the other hand, vendor prefixes are treated as non-standard and therefore technically invalid CSS.

The are tolerated and widely used, so even the validator itself now includes an option for Vendor Extensions (under More Options box). There you can switch errors into warnings, so the site validates tentatively.

We will keep these vendor prefixes so our plugin is backwards compatible.

thanks
Viktor