Source: Schema.org v30.1 vocabulary. Official constraintProperty property definition.
What does constraintProperty mean?
Indicates a property used as a constraint. For example, in the definition of a [[StatisticalVariable]]. The value is a property, either from within Schema.org or from other compatible (e.g. RDF) systems such as DataCommons.org or Wikidata.org.
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