Schema.org is a list of types and properties that search engines and other parsers agreed to understand. Organization. LocalBusiness. PostalAddress. The list is public. Using it does not make a page famous.
The rule that matters
Markup must describe the thing on the page. A roofer page should not be marked as an article about “best roofers” with a fake author. A Bronze file should not carry a GovernmentPermit node for a filing nobody attested.
Where firms overreach
They copy a competitor’s graph. They mark every employee as a founder. They add Review markup they cannot show. Parsers that used to be hungry are now suspicious. Suspicion is worse than silence.
Read why this exists. Check a name in the registry. Or start with a free check. Gold is $297 a year after the website is proved.