While trying to solve a validation issue in one of my web sites I came across the following forum posting. It was stated so well that I decided to re-post it here. I want to encourage my readers to understand that when a page doesn’t pass validation, it doesn’t mean that the page is “broken”. Please read on…
Validation is a tool. It is not a goal. It is for catching syntax errors. It is for you to determine whether to worry about the error or not.
The animations module is in working draft status.
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It would be foolish for vendors to implement a module that is likely incomplete and certain to be modified in ways that would affect that implementation. That is why we have the -[vendor]- prefix. It’s a temporary implementation until the dust settles.
If your client is insisting on a validation button, you’ll have to explain why that’s not possible. Using css3 is a progressive enhancement; in this case from both sides. Older browsers won’t support css3 animations, and css3 won’t validate the proprietary prefix that allows for working draft properties that are not a part of the specification yet.
Gary Tuner, (Moderator on http://csscreator.com)