Source: Schema.org v30.1 vocabulary. Official readonlyValue property definition.
What does readonlyValue mean?
Whether or not a property is mutable. Default is false. Specifying this for a property that also has a value makes it act similar to a "hidden" input in an HTML form.
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