WordPress announced that version 5.3 will use improved coding that will be closer to standards compliant HTML. There are good reasons why it valid HTML should be considered important for SEO. While the WordPress HTML will not be 100% valid, this update is a step in the right direction.
The release date is tentatively scheduled for November 12, 2019. For many this might seem like too little and too late. Nevertheless, WordPress is arguably the most important content management system at the moment. This means that attaining valid HTML for a website is closer now for a great many sites across the web.
WordPress 5.3 Fixes Type Attribute Issue
The improvement is focused on how script and style tags are coded. Prior to HTML5, it was mandatory to use the “type” attribute to tell browsers that the script or style was text.
HTML5 eliminated the need for the “type” attribute. The change caused HTML5 sites that continued using the “type” attribute to render as invalid HTML.
Different Levels of Validation Messages
There are different levels of validation messages. There are warnings, which are considered relatively minor and there are errors, which are more important.
This coding error resulted in a validation warning but did not trigger an error message. Perhaps because it was seen as a harmless oversight the invalid code continued to be present in WordPress.
Official WordPress Announcement
This is how the official WordPress announcement described what is changing in version 5.3:
“In HTML5, the type attribute is not required for the