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Standard extensions

On top of plain JSON Schema and JSON-LD, OO-LD defines a small set of extensions. They fall into two groups.

JSON-LD side

  • Processing mode (@version) - OO-LD relies on JSON-LD 1.1 features (scoped contexts), so contexts should declare "@version": 1.1.
  • Multi-Mapping / synonyms - a <property>* shorthand documents alternative IRI mappings inline; x-oold-context is the structured form (more than two mappings, override under composition, ontology-family prioritization, SSSOM round-trip).

JSON Schema side

  • JSON Schema 2020-12 is the required dialect (composition places $ref next to sibling keywords, only honored from 2019-09 onward).
  • Multilanguage - x-oold-multilang-title / x-oold-multilang-description localize a schema's own labels; instance values are localized with standard JSON-LD language maps.
  • Range (x-oold-range) - constrains the type of a referenced object (an IRI, a union of IRIs, or an inline subschema); references inside it use x-oold-ref, not $ref.
  • Reverse properties (x-oold-reverse-*) - edit a symmetric relation from both sides, mapped with JSON-LD @reverse.
  • UI Generation (x-oold-ui-*) - a portable vocabulary of form/view hints (widget, order, grouping, visibility, enum labels), with vendor pass-through (x-jedison-*) and delivery inline or via an overlay.

For the normative rules and worked examples of every keyword above, see Standard Extensions in the specification.