Sparqdown Document
A Sparqdown Document is a Document whose source is written in the Sparqdown language — a TriG-style graph section followed by a Markdown-style body. The registry parses the source at ingest, builds the semantic model, extracts metadata (labels, type assertions, dependency edges, bindings, claims), and stores the metadata projection in the Version graph. The source itself is not retained by the registry; the authoring tool owns the source at the address recorded via sdg:sourceAddress.
Multi-typing
sdg:SparqdownDocument is rarely the only Type on a document. Almost every document in the Index is also something more specific: sdg:Workspace, sdg:TypeDefinition, or a domain Type like org:Recipe or org:Runbook. Multi-typing is standard RDF; rdf:type can carry many classes and all their SHACL shapes apply in intersection.
Not the same as PureFile
A document typed sdg:PureFile has no Sparqdown body — the registry records only metadata (content hash, mimeType, source address). Contracts, images, CAD files live this way. A document can be both sdg:SparqdownDocument or sdg:PureFile, but not both at once.
Renderer
The viewer dispatches on the set of types. For sdg:SparqdownDocument the default renderer reads the body tree from sd:body and walks children. Specific subtypes can add components in declared slots — see ScriptDefinition for the discovery mechanism.