I am trying to create a piece of structured data for my articles, and I am confused about the use of the reviewedBy property.

By definition, the reviewedBy property can only be nested inside the WebPage type. However, I’ve seen sites using the reviewedBy property individually (without being nested) and Google doesn’t recognize this as an issue, on the other hand, the Schema Markup Validator does.

How is that possible?

{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "Best Bread Recipe in 2025",
  "author": {
    "@type": "Person",
    "name": "John Smith",
    "URL": "https://example.com/bread-recipe"
  },
  "reviewedBy": {
  "@type": "Person",
  "name": "Sara Smith"
  }
}

Here’s also an image of the code in the official Rich Results Test validator and Schema.org validator:

Thanks!