RDF Prefixes in datasets.yaml¶

This guide covers how to use RDF (Resource Description Framework) prefixes in datasets.yaml to add semantic metadata to your datasets. For the full specification including datapackage.json output and advanced use cases, see Data Package Metadata Extensibility.

Standard Prefixes¶

Sunstone includes these built-in prefixes that are always available (no need to declare them):

Prefix	Namespace	Purpose
`dcat:`	`http://www.w3.org/ns/dcat#`	Data Catalog Vocabulary
`dct:`	`http://purl.org/dc/terms/`	Dublin Core Terms
`dwc:`	`http://rs.tdwg.org/dwc/terms/`	Darwin Core (biodiversity)
`gtio-i:`	`https://sunstone.institute/rdf/gtio/0.3/interventions#`	GTIO interventions vocabulary
`gtio-t:`	`https://sunstone.institute/rdf/gtio/0.3/threats#`	GTIO threats vocabulary
`prov:`	`http://www.w3.org/ns/prov#`	W3C Provenance Ontology
`qudt:`	`http://qudt.org/schema/qudt/`	Quantities, Units, Dimensions
`rdf:`	`http://www.w3.org/1999/02/22-rdf-syntax-ns#`	RDF syntax
`rdfs:`	`http://www.w3.org/2000/01/rdf-schema#`	RDF Schema
`schema:`	`http://schema.org/`	Schema.org vocabulary
`si:`	`https://sunstone.institute/rdf/vocab#`	Sunstone-specific properties
`si30:`	`https://sunstone.institute/rdf/threat/`	Sunstone threat references
`skos:`	`http://www.w3.org/2004/02/skos/core#`	Simple Knowledge Organization
`sosa:`	`http://www.w3.org/ns/sosa/`	Sensor, Observation, Sample, Actuator

The full set is exported as sunstone.STANDARD_RDF_PREFIXES for programmatic use.

Defining Prefixes¶

Prefixes can be defined at three levels, with this precedence order (highest first):

Dataset-level — on an individual input or output
Top-level — at the root of datasets.yaml
Defaults section — in the defaults: block

Using the defaults section (recommended)¶

Define prefixes once and they apply to all datasets:

defaults:
  rdfPrefixes:
    si: "https://sunstone.institute/rdf/vocab#"
    si30: "https://sunstone.institute/rdf/threat/"
    dcat: "http://www.w3.org/ns/dcat#"

outputs:
  - name: Climate Dataset
    slug: climate-dataset
    location: outputs/climate.csv
    si:monitorsThreat: si30:27
    si:category: environmental
    dcat:theme: climate
    fields:
      - name: year
        type: integer

Top-level prefixes¶

rdfPrefixes:
  si: "https://sunstone.institute/rdf/vocab#"
  si30: "https://sunstone.institute/rdf/threat/"

outputs:
  - name: Climate Dataset
    slug: climate-dataset
    location: outputs/climate.csv
    si:monitorsThreat: si30:27
    fields:
      - name: year
        type: integer

Per-dataset override¶

A dataset can override inherited prefixes:

defaults:
  rdfPrefixes:
    si: "https://sunstone.institute/rdf/vocab#"

outputs:
  - name: Special Dataset
    slug: special-dataset
    location: outputs/special.csv
    rdfPrefixes:
      si: "https://other.example.com/vocab#"  # overrides default
    si:customProp: value
    fields:
      - name: id
        type: integer

Adding RDF Properties¶

Any key containing : (or starting with http:///https://) on a dataset entry is treated as a custom RDF property. Standard dataset fields (name, slug, location, fields, source, strict, lineage, rdfPrefixes, publish) are excluded.

Using prefixed names¶

outputs:
  - name: Climate Dataset
    slug: climate-dataset
    location: outputs/climate.csv
    si:monitorsThreat: si30:27      # both key and value use prefixes
    si:category: environmental       # value is a plain string
    dcat:theme: climate
    fields:
      - name: year
        type: integer

Using full URIs¶

You can also use full URIs directly without defining prefixes:

outputs:
  - name: My Dataset
    slug: my-dataset
    location: outputs/data.csv
    https://sunstone.institute/rdf/vocab#datasetType: observational
    fields:
      - name: id
        type: integer

Default Properties¶

RDF properties in the defaults: section are inherited by all datasets:

defaults:
  rdfPrefixes:
    si: "https://sunstone.institute/rdf/vocab#"
  si:organization: "Sunstone Institute"
  si:license: "CC-BY-4.0"

outputs:
  - name: Dataset 1
    slug: dataset-1
    location: outputs/data1.csv
    si:theme: climate
    fields:
      - name: id
        type: integer

  - name: Dataset 2
    slug: dataset-2
    location: outputs/data2.csv
    si:theme: biodiversity
    fields:
      - name: id
        type: integer

Both datasets inherit si:organization and si:license from defaults. Dataset-level properties override defaults when they share the same key.

Prefix Expansion¶

When building a datapackage (sunstone package build), prefixes in both keys and values are expanded to full URIs:

# In datasets.yaml
si:monitorsThreat: si30:27

Becomes in datapackage.json:

"https://sunstone.institute/rdf/vocab#monitorsThreat": "https://sunstone.institute/rdf/threat/27"

Non-string values (numbers, booleans, lists) are preserved as-is without expansion.

Automatic Type Properties¶

Every generated datapackage.json automatically includes DCAT type annotations:

Package level: rdf:type -> dcat:Dataset
Resource level: rdf:type -> dcat:Distribution

No configuration needed — this makes all generated packages compatible with DCAT-based data catalogs.

Methodology Property¶

The si:methodology property has special handling. When its value is a local file path, it is resolved as a relative URI against publish.as during publishing:

publish:
  enabled: true
  to: gs://my-bucket/datasets/project/
  as: https://cdn.example.com/datasets/project/

defaults:
  rdfPrefixes:
    si: "https://sunstone.institute/rdf/vocab#"
  si:methodology: docs/default-methodology.md

outputs:
  - name: Climate Dataset
    slug: climate-dataset
    location: outputs/climate.csv
    si:methodology: docs/climate-methodology.md  # per-dataset override
    fields:
      - name: year
        type: integer

On publish, the value becomes https://cdn.example.com/datasets/project/docs/climate-methodology.md and the file is uploaded alongside the data.