"async" is not a member of a group specified for any attribute
adsense, html, w3c-validation
Solution
The `async` attribute (for the `script` element) and the `data-*` attributes were introduced with HTML5.
You likely get the errors because you are using an earlier HTML version (like HTML 4.01).
To fix this, you have to use HTML5 or a later version. The latest version can always be found at https://www.w3.org/TR/html/.
For many documents it’s sufficient to switch to the new DOCTYPE:
<!DOCTYPE html>
Problem
Running my site through the W3C validator (and in other validators), I'm getting the following errors with my Google Ads: - `async` is not a member of a group specified for any attribute - there is no attribute `data-ad-client` - there is no attribute `data-ad-slot` Is there anyway to correct these? I'd love to see the site pass 100%.