Thing > Property > schemaVersion

Indicates (by URL or string) a particular version of a schema used in some CreativeWork. For example, a document could declare a schemaVersion using an URL such as http://schema.org/docs/releases.html#v1.91 if precise indication of schema version was required by some application.

Usage: Fewer than 10 domains
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Values expected to be one of these types
Text
URL
Used on these types
CreativeWork

Schema Version 1.999999