DCAT-US 3.0: Identifiers and Relationships

Identifiers and Relationships

Supporting classes for identifiers, relationships, checksums, and controlled concepts used to describe and connect resources.

Class Identifier #

A unique identifier and optionally it’s scheme and other relevant information

• Type: combining
• Additional properties: Any type allowed

Any of:

• Simple string identifier
• Identifier as a complex object

Identifier > anyOf > Simple string identifier #

• Type: string

Identifier > anyOf > Identifier as a complex object #

• Type: object
• Additional properties: Any type allowed

Identifier > anyOf > Identifier as a complex object > @id #

Requirement: Optional

• Type: string
• Format: iri

Identifier > anyOf > Identifier as a complex object > @type #

Requirement: Optional

• Type: string
• Default: "Identifier"

Identifier > anyOf > Identifier as a complex object > creator #

Requirement: Optional

the agency that manages the identifier scheme

• Type: null or Organization

Identifier > anyOf > Identifier as a complex object > issued #

Requirement: Optional

The date of formal issuance (e.g., publication) of the Identifier

• Type: null or object

Identifier > anyOf > Identifier as a complex object > notation #

Requirement: Optional

abbreviation or code from code lists for an identifier

• Type: null or string

Identifier > anyOf > Identifier as a complex object > schemaAgency #

Requirement: Optional

The name of the agency that issued the identifier

• Type: null or string

Identifier > anyOf > Identifier as a complex object > version #

Requirement: Optional

version of the identifier scheme

• Type: null or string

Class Relationship #

Additional information about how one resource is related to another

• Type: object
• Additional properties: Any type allowed

Example:

{
    "@type": "Relationship",
    "hadRole": "isInputTo",
    "relation": "https://example.gov/models/climate-prediction"
}

Relationship > hadRole #

Title: role

Requirement: Mandatory

The function of an entity or agent with respect to a dataset

• Type: string
• Required: Yes

Examples:

"isInputTo"

"dataProvider"

Relationship > relation #

Requirement: Mandatory

The entity related to the dataset. This string should unambiguously identify the related resource using an appropriate identifier.

• Type: string
• Required: Yes

Examples:

"https://example.gov/models/climate-prediction"

"https://example.gov/organizations/national-weather-service"

Relationship > @id #

Requirement: Optional

• Type: string
• Format: iri

Example:

"https://example.gov/relationships/dataset-001-data-provider"

Relationship > @type #

Requirement: Optional

• Type: string
• Default: "Relationship"

Class Checksum #

A mechanism that can be used to verify that the contents of a distribution have not changed

• Type: object
• Additional properties: Any type allowed

Example:

{
    "@type": "Checksum",
    "algorithm": "SHA-256",
    "checksumValue": "a1b2c3d4e5f6789012345678901234567890abcdef1234567890abcdef123456"
}

Checksum > algorithm #

Requirement: Mandatory

The algorithm used to produce the checksum

• Type: string
• Required: Yes

Example:

"SHA-256"

Checksum > checksumValue #

Requirement: Mandatory

A lower case hexadecimal encoded digest value produced using a specific algorithm

• Type: string
• Required: Yes

Examples:

"a1b2c3d4e5f6789012345678901234567890abcdef1234567890abcdef123456"

"a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e"

Checksum > @id #

Requirement: Optional

• Type: string
• Format: iri

Example:

"https://example.gov/checksums/dataset-001-sha256"

Checksum > @type #

Requirement: Optional

• Type: string
• Default: "Checksum"

Class Concept #

A controlled term or label, optionally drawn from a concept scheme

• Type: combining
• Additional properties: Any type allowed

Examples:

"Environment"

"Climate Science"

{
    "@type": "Concept",
    "prefLabel": "Environment"
}

{
    "@type": "Concept",
    "prefLabel": "Climate Science",
    "definition": "The scientific study of climate patterns and change.",
    "inScheme": {
        "@id": "https://example.gov/concept-schemes/science-domains",
        "@type": "ConceptScheme",
        "title": "Science Domains"
    }
}

{
    "@id": "https://example.gov/concepts/environment",
    "@type": "Concept",
    "prefLabel": "Environment",
    "altLabel": "Ecology",
    "definition": "The natural world, including air, water, land, plants, and animals, especially as affected by human activity.",
    "notation": [
        "ENV",
        "E01",
        "ENVI"
    ],
    "inScheme": {
        "@id": "https://example.gov/concept-schemes/data-themes",
        "@type": "ConceptScheme",
        "version": "2.0",
        "description": "DCAT-US approved themes for categorizing datasets",
        "title": "Data Themes"
    }
}

Any of:

• Concept
• item 1

Concept > anyOf > Concept #

The value of the concept, expressed as a string. This is only used when the concept is not further described by the properties of the Concept object and is not linked to a concept scheme.

• Type: string

Examples:

"Environment"

"Climate Science"

Concept > anyOf > item 1 #

• Type: object
• Additional properties: Any type allowed

Examples:

{
    "@type": "Concept",
    "prefLabel": "Environment"
}

{
    "@type": "Concept",
    "prefLabel": "Climate Science",
    "definition": "The scientific study of climate patterns and change.",
    "inScheme": {
        "@id": "https://example.gov/concept-schemes/science-domains",
        "@type": "ConceptScheme",
        "title": "Science Domains"
    }
}

Concept > anyOf > item 1 > @id #

Requirement: Optional

• Type: string
• Format: iri

Example:

"https://example.gov/concepts/environment"

Concept > anyOf > item 1 > @type #

Requirement: Optional

• Type: string
• Default: "Concept"

Concept > anyOf > item 1 > altLabel #

Title: alternate label

Requirement: Optional

Alternative label for a concept

• Type: null or string

Example:

"Ecology"

Concept > anyOf > item 1 > definition #

Requirement: Optional

Definition of the controlled vocabulary term

• Type: null or string

Examples:

"The scientific study of climate patterns and change."

"The natural world, including air, water, land, plants, and animals, especially as affected by human activity."

Concept > anyOf > item 1 > inScheme #

Requirement: Optional

Concept scheme defining this concept

• Type: object
• Additional properties: Any type allowed
• Defined in: ConceptScheme

Examples:

{
    "@id": "https://example.gov/concept-schemes/science-domains",
    "@type": "ConceptScheme",
    "title": "Science Domains"
}

{
    "@id": "https://example.gov/concept-schemes/data-themes",
    "@type": "ConceptScheme",
    "version": "2.0",
    "description": "DCAT-US approved themes for categorizing datasets",
    "title": "Data Themes"
}

Concept > anyOf > item 1 > notation #

Requirement: Optional

List of abbreviations or codes from code lists for the Concept

• Type: null or array of string

Example:

[
    "ENV",
    "E01",
    "ENVI"
]

Concept > anyOf > item 1 > prefLabel #

Title: preferred label

Requirement: Optional

Preferred label for the term

• Type: string
• Required: Yes

Examples:

"Environment"

"Climate Science"

Class ConceptScheme #

A controlled vocabulary or other list of approved terms for a concept

• Type: object
• Additional properties: Any type allowed

Example:

{
    "@type": "ConceptScheme",
    "title": "Science Domains",
    "description": "A classification scheme for scientific research domains.",
    "issued": "2020-01-01"
}

ConceptScheme > title #

Requirement: Mandatory

The title of the concept scheme

• Type: string
• Required: Yes

Examples:

"Science Domains"

"Federal Data Classification Scheme"

ConceptScheme > description #

Requirement: Recommended

A description of the concept scheme

• Type: null or string

Examples:

"A classification scheme for scientific research domains."

"A controlled vocabulary for classifying federal government data assets by sensitivity and access requirements."

ConceptScheme > @id #

Requirement: Optional

• Type: string
• Format: iri

Example:

"https://example.gov/concept-schemes/data-classification"

ConceptScheme > @type #

Requirement: Optional

• Type: string
• Default: "ConceptScheme"

ConceptScheme > created #

Title: creation date

Requirement: Optional

The date on which the Concept Scheme was first created

• Type: null or object

Examples:

"2020"

"2024-01-15T10:30:00Z"

"2024-01-15"

"2024-01"

ConceptScheme > issued #

Title: publication date

Requirement: Optional

The date of formal issuance (e.g., publication) of the concept scheme

• Type: null or object

Examples:

"2020-01-01"

"2020"

"2024-01-15T10:30:00Z"

"2024-01"

ConceptScheme > modified #

Title: update/modification date

Requirement: Optional

The most recent date at which the concept scheme was changed or modified

• Type: null or object

Examples:

"2024"

"2024-01-15T10:30:00Z"

"2024-01-15"

"2024-01"

ConceptScheme > version #

Title: version info

Requirement: Optional

A version number or other version designation of the concept scheme

• Type: null or string

Example:

"2.0.1"