There is a difference between what you see at Schema.org and what Google publishes at its Google Search developer documents for structured data rich results. The short difference is that what Google publishes is what you can potentially see surface in the Google search results but what schema.org publishes you probably won’t.

In short, if the structured data is not one of the dozens of structured data items listed in this gallery then you won’t have a chance of showing up with richer search results in Google Search. That means if you use something that is published on Schema.org but that is not listed at the Google developer site then you won’t benefit from the enhanced listing in Google Search. For example, you won’t see stars, reviews, carousel images, and other forms of richened up search results.

John Mueller, a Search Advocate at Google, talked about this in a video hangout on Friday, January 15, 2021. He was answering the following question at the 49:44 mark into the video. The question was “In the schema.org website, there are different suggestions for travel sector, such as tourist trip, travel agency, or trip. Are the schema types mentioned above supported or relevant for Google indexing and ranking? If not, what would be the most suitable structured data type for a trip landing page?”

Does Google support schema.org?

Google supports some of schema.org, but only those elements mentioned in the Google developer guides. John Mueller of Google responded in detail but summed it up saying “we support a subset of the functionality, or the different types of markup, from schema.org.” “And those are the things that we would show in the search results,” he added “and everything else is essentially kind of, I don’t know, more like a nice-to-have.”

Here is his full response:

Here is the video embed so you can watch it yourself:

Forum discussion at YouTube Community.