VSON represents what is in a picture as a typed, validatable RDF graph: the entities depicted, the qualities they bear, the spatial and temporal facts that hold between them, and the frame the scene is seen through. The OWL ontology below declares the terms, and the SHACL shapes decide whether a given document is well-formed — well-formedness is a validation result here, not a convention.
This host serves the namespace documents themselves. The project — the transpilers, the CLI, the test corpus and the specification — lives in the GitHub repository linked above.
/v1/ontology.ttl — the VSO TBox: entity
taxonomy, frame layer, reification node classes and the closed value
vocabularies the shapes validate against.
Namespace https://w3id.org/vson/v1/ontology#, written
vso: in every VSON document. The prefix the vocabulary
publishes for registries is vson:, because
vso: is already the Vehicle Sales Ontology's; a prefix is an
abbreviation either way, and the namespace above is the name.
/v1/rcc8.ttl — the eight RCC-8 base relation
names, as a closed vocabulary of values for vso:rcc.
Namespace https://w3id.org/vson/v1/rcc8#, prefix
rcc:.
/v1/allen.ttl — Allen's thirteen base
relations on intervals, declared as object properties between perdurants,
with their inverses.
Namespace https://w3id.org/vson/v1/allen#, prefix
allen:.
/v1/shapes.ttl — the shapes a conformant
VSON document must satisfy.
Shape names are minted in https://w3id.org/vson/v1/shapes#,
prefix vss:.
/v1/shapes-relaxed.ttl — the partial
validation profile, for documents still being extracted or repaired. It
shares the vss: namespace with the strict profile; the two
are separate documents, not separate vocabularies.
/v1/context.jsonld — binds the Composition-level reference properties to their VSO IRIs so a JSON-LD processor materializes the same graph the Turtle surface carries. It maps names; it does not constrain them. The shapes above are what enforce well-formedness.
/v1/schema/vson-output.schema.json
— the extractor response envelope.
/v1/schema/vson-jsonld.schema.json
— the structural skeleton of the JSON-LD scene form.
Both are structural only. A payload can satisfy either schema and still fail SHACL.
Canonical names. The canonical IRIs are
https://w3id.org/vson/v1/… — permanent identifiers under the
W3C Permanent Identifier Community Group. They dereference: since
2026-07-31 each one redirects to the matching document on this host, so
https://w3id.org/vson/v1/ontology resolves to
/v1/ontology.ttl and a reasoner can follow
the name without being told where the bytes live. Cite the canonical
names, not these paths: they are the identifiers, this host is only where
the bytes currently sit.