Schema Validator Error: The property noopener is not recognized by the schema (e.g. schema.org) for an object of type Article.

[btakita]

Hi everyone, I ran the schema validator on rdfa markup that has an <a target=_blank rel=noopener> tag in an Article. The validator gives the error:

The property noopener is not recognized by the schema (e.g. schema.org) for an object of type Article.

Is this a problem with the validator? Since rel=noopener or rel="noopener noreferrer" fixes a security vulnerability when target=_blank. Is there a workaround?