Source: Schema.org v30.1 vocabulary. Official diagram property definition.
What does diagram mean?
An image containing a diagram that illustrates the structure and/or its component substructures and/or connections with other structures.
Used on types (domainIncludes)
Expected value types (rangeIncludes)
Schema.org domainIncludes and rangeIncludes are descriptive guidance, not strict validation prohibitions. Check the official reference for updates.
Related reference
Browse all Schema.org types and properties · Google feature support status