DCAT-US Schema v3.0 — Dataset fields

Overview

Field-level reference for the DCAT-US v3.0 Dataset class. The Dataset is the primary unit of a federal data inventory.

Source

data.gov

Category

Keywords

DCAT,

Details

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Overview

The Dataset class describes an individual dataset or API. Most agency data inventory work happens at this level. Required fields in v3.0: title, description, publisher, contactPoint, identifier All other fields are Optional unless noted. Fields that were required in v1.1 but are no longer schema-required in v3.0 are noted below. Agencies should consult the current OMB policy guidance for any fields that remain required. —

Transition from DCAT-US v1.1 to v3.0

If your agency is upgrading from v1.1, most of your existing dataset records will carry forward with minimal changes. The required fields are largely the same. The main things to be aware of are: modified no longer accepts repeating intervals; temporal and spatial now use structured objects instead of strings; accessLevel is replaced by accessRights; and license should move to the Distribution level. The table at the bottom of this page summarizes all field-level changes from v1.1. —

Discovery and context

These fields are new in v3.0 and help users understand what a dataset is for, what it covers, and any limitations on its use. They are all optional but strongly encouraged for publicly visible datasets.

Field Required Type Description
purpose Optional string The purpose of the dataset — why it was created and what problem it addresses. Example: "To provide comprehensive climate observations for research, planning, and decision-making."
liabilityStatement Optional string A statement clarifying limitations of responsibility, qualifications on accuracy or completeness, or absence of endorsement by the publisher. Example: "This dataset is provided as-is without warranty. Users are responsible for determining fitness for their intended use."
scopeNote Optional string A usage note clarifying what the dataset includes and excludes, or guidance on how it should be interpreted. Example: "This dataset contains raw observational data. For derived products such as monthly averages see related datasets."
creator Optional object The person or organization that created the dataset, if different from the publisher. References the Agent class. Example: {"name": "National Climate Data Center"}
provenance Optional array of strings Plain-language statements about the lineage of the dataset — how the data was collected, processed, and quality-controlled. Example: ["Data collected from automated weather stations at 2,500 locations.", "Quality control applied per WMO guidelines."]

Core fields

Field Required Type Description
title Mandatory string Human-readable name of the dataset. Should be in plain English with sufficient detail for search and discovery. Avoid acronyms.
description Mandatory string Human-readable description with sufficient detail for a user to quickly understand whether the dataset is of interest.
publisher Mandatory object The publishing entity and optionally its parent organization(s). References the Organization class. At a minimum, provide name. Optionally add prefLabel (preferred legal name), altLabel (acronym), and subOrganizationOf (array of parent organizations).
contactPoint Mandatory object or array Contact person's name and email for the dataset. References the Kind class. Must include fn (full name) and hasEmail (formatted as mailto:name@agency.gov). Can be a single object or an array for multiple contacts. Optionally add tel and organization-name.
identifier Mandatory string A unique identifier for the dataset. Must be unique across the agency's catalog and remain fixed over time. Use a persistent URI where possible.
keyword Recommended array of strings Tags to help users discover the dataset. Include both technical and non-technical terms. (Required in v1.1)
modified Recommended string (ISO 8601) Most recent date the dataset was changed or updated. (Required in v1.1). Note for agencies upgrading from v1.1: If you currently use a repeating interval like R/P1D or R/P1Y in this field, that format is no longer valid in v3.0. Set modified to the actual date the data last changed (e.g., 2024-06-01) and use accrualPeriodicity to express update frequency.
issued Optional string (ISO 8601) Date of formal release.
language Optional array of strings ISO 639-1 two-letter language codes (e.g., en, es, fr). Note: v1.1 used RFC 5646 tags like en-US — v3.0 simplifies to two-letter codes only.
landingPage Recommended object A Document object with a title and accessURL pointing to a human-friendly hub or landing page for all resources tied to the dataset. Example: {"@type": "Document", "title": "Dataset Homepage", "accessURL": "https://agency.gov/dataset"}
theme Recommended array of Concept objects Each Concept requires a prefLabel. Example: [{"prefLabel": "Climate Science"}]. Can reference a ConceptScheme for controlled vocabulary linkage.
accrualPeriodicity Optional string Accepts plain-language codes (e.g., daily, weekly, monthly, quarterly, annually, irregular), ISO 8601 repeating duration format (e.g., R/P1Y), or Dublin Core frequency terms. Plain-language codes are preferred.
conformsTo Optional array of Standard objects Each Standard should include a title and optionally an identifier and issued date. Example: [{"@type": "Standard", "title": "ISO 19115", "identifier": "https://www.iso.org/standard/53798.html"}]. A dataset can conform to multiple standards.
describedBy Recommended object A Distribution object describing the data dictionary. Example: {"@type": "Distribution", "title": "Data Dictionary", "downloadURL": "https://agency.gov/dict.pdf", "mediaType": "application/pdf"}. The describedByType field from v1.1 is no longer needed — express the format as mediaType within this Distribution object.

Distribution and access

Field Required Type Description
distribution Conditional array of objects A container for one or more Distribution objects describing how the dataset can be accessed or downloaded. Required if the dataset has an accessURL or downloadURL. See Distribution fields. In v3.0, license should be included on each Distribution object rather than at the Dataset level. If all distributions share the same license, add it to each one.
sample Optional array of objects Links to sample distributions of the dataset.

Access and rights

Field Required Type Description
accessRights Optional string Information about who can access the dataset and under what conditions. In v1.1 this was the accessLevel field with three fixed values (public, restricted public, non-public). In v3.0 accessRights is a free-text string. The value public remains valid. For restricted datasets, write a plain-language explanation of the restriction and how to request access.
rights Recommended array of strings Rights statements not already covered by license or accessRights — for example, copyright statements, attribution requirements, or policy restrictions on use. Example: ["Data is in the public domain under 17 USC 105.", "Please cite the National Climate Data Center when using this data."]. In v1.1 this was a single string with a 255-character limit. In v3.0 it is an array with no character limit.
rightsHolder Optional object An agent owning or managing rights over the dataset. References the Agent class.
license Optional string (URL) The license or public domain dedication status of the dataset. Provide as a URL. See Open Licenses. In v3.0, license is more correctly expressed at the Distribution level per W3C DCAT. Including it here at the dataset level is supported, but agencies are encouraged to move license to each Distribution object.

Spatial and temporal

Field Required Type Description
spatial Recommended array of Location objects Spatial coverage of the dataset. References the Location class. (Was a string in v1.1; now uses the Location class.) Minimum upgrade: {"@type": "Location", "prefLabel": "United States"}. For geospatial precision, add a bbox as a WKT string: "POLYGON((-125 24, -66 24, -66 50, -125 50, -125 24))" or as a GeoJSON Polygon object.
temporal Recommended array of PeriodOfTime objects Temporal coverage of the dataset. References the PeriodOfTime class. Note for agencies upgrading from v1.1: The v1.1 string format (e.g., 2000-01-15T00:00:00Z/2010-01-15T00:00:00Z) is no longer valid. Use a PeriodOfTime object: {"@type": "PeriodOfTime", "startDate": "2000-01-15", "endDate": "2010-01-15"}. Open-ended periods are valid — you can omit either startDate or endDate.
spatialResolutionInMeters Optional string A numeric value expressed as a string (e.g., "1000" for 1 kilometer resolution).
temporalResolution Optional string (ISO 8601 duration) Minimum time period resolvable in the dataset. New in v3.0.

Versioning and series

Field Required Type Description
version Optional string The version indicator for this dataset.
versionNotes Optional string A description of changes between this version and the previous version.
hasCurrentVersion Optional string (IRI) A link to the current version of the dataset.
hasVersion Optional array Links to known versions of the dataset.
previousVersion Optional string (IRI) A link to the previous version of the dataset.
replaces Optional array Datasets that this dataset replaces.
inSeries Optional array of DatasetSeries objects A DatasetSeries to which this dataset belongs. See DatasetSeries fields. In v1.1, isPartOf was used to group datasets into a collection. In v3.0, use inSeries for temporal series membership, or document collection membership at the parent dataset level using hasPart.

When to use which versioning field

  • Use inSeries when your dataset is one edition in a recurring sequence — for example, the FY2024 edition of an annual survey. Create a DatasetSeries record for the series as a whole and reference it here. See DatasetSeries fields. - Use version when you are publishing a corrected or updated version of the same dataset — for example, version 2.1 of a reference file. Pair it with versionNotes to describe what changed. - Use hasVersion to link a dataset record to all its known versions, and hasCurrentVersion to point users to the latest one. - Use replaces when a dataset supersedes one or more previous datasets entirely — not just an update, but a replacement. These fields can be used together. A dataset can belong to a series via inSeries and also carry a version number and versionNotes. —

    Provenance and quality

Field Required Type Description
provenance Optional array of strings Plain-language statements about the lineage of the dataset — how the data was collected, processed, and quality-controlled.
source Optional array Datasets from which this dataset was derived.
wasGeneratedBy Optional array Activities that generated this dataset. References the Activity class.
hasQualityMeasurement Optional array Quality measurements associated with the dataset. References the QualityMeasurement class.

Federal government fields

These fields were introduced in DCAT-US v1.1 for federal agency use. They are not defined in the v3.0 core schema but agencies should continue populating them under existing OMB policy (M-13-13 and the OPEN Government Data Act) until updated guidance is issued. The v3.0 schema will not reject records that include them.

Field Required Type Description
bureauCode Policy-dependent array of strings Agency and bureau code from OMB Circular A-11, Appendix C. Format: 015:11.
programCode Policy-dependent array of strings Primary program related to this dataset, from the Federal Program Inventory. Format: 015:001.
accessLevel Policy-dependent string The degree to which the dataset could be made publicly available. One of: public, restricted public, non-public. (Required in v1.1)
primaryITInvestmentUII Optional string IT Unique Investment Identifier linking the dataset to an IT investment in Exhibit 53.
systemOfRecords Optional string (URL) URL to the System of Records Notice (SORN) if this dataset is a Privacy Act system of records.
dataQuality Optional boolean Whether the dataset meets the agency's Information Quality Guidelines (true or false). Not in v3.0 schema — use hasQualityMeasurement for structured quality reporting going forward.

Example

A minimal Dataset record meeting the v3.0 required fields:

{
  "@type": "Dataset",
  "title": "Agency Travel Data FY2024",
  "description": "Records of official travel expenditures by agency employees during fiscal year 2024, including destination, purpose, and cost.",
  "identifier": "https://www.agency.gov/data/travel-fy2024",
  "publisher": {
    "@type": "Organization",
    "name": "Office of the Chief Financial Officer",
    "subOrganizationOf": [
      {
        "@type": "Organization",
        "name": "Example Federal Agency"
      }
    ]
  },
  "contactPoint": {
    "@type": "Kind",
    "fn": "Jane Smith",
    "hasEmail": "mailto:jane.smith@agency.gov"
  }
}

A more complete record showing commonly used fields:

{
  "@type": "Dataset",
  "title": "Agency Travel Data FY2024",
  "description": "Records of official travel expenditures by agency employees during fiscal year 2024, including destination, purpose, and cost.",
  "identifier": "https://www.agency.gov/data/travel-fy2024",
  "publisher": {
    "@type": "Organization",
    "name": "Office of the Chief Financial Officer",
    "subOrganizationOf": [
      {
        "@type": "Organization",
        "name": "Example Federal Agency"
      }
    ]
  },
  "contactPoint": {
    "@type": "Kind",
    "fn": "Jane Smith",
    "hasEmail": "mailto:jane.smith@agency.gov",
    "tel": "+1-202-555-0100",
    "organization-name": "Office of the Chief Financial Officer"
  },
  "keyword": ["travel", "expenditure", "fiscal year", "FY2024"],
  "modified": "2024-10-15",
  "accrualPeriodicity": "annually",
  "accessRights": "public",
  "purpose": "To provide transparency into federal employee travel expenditures.",
  "temporal": [
    {
      "@type": "PeriodOfTime",
      "startDate": "2023-10-01",
      "endDate": "2024-09-30"
    }
  ],
  "spatial": [
    {
      "@type": "Location",
      "prefLabel": "United States"
    }
  ],
  "distribution": [
    {
      "@type": "Distribution",
      "title": "FY2024 Travel Data (CSV)",
      "description": "Full travel records as a comma-separated values file.",
      "downloadURL": "https://www.agency.gov/data/travel-fy2024.csv",
      "mediaType": "text/csv",
      "format": "CSV",
      "license": "https://creativecommons.org/publicdomain/zero/1.0/"
    },
    {
      "@type": "Distribution",
      "title": "Travel Data REST API",
      "description": "A fully queryable REST API returning JSON.",
      "accessURL": "https://api.agency.gov/travel/",
      "format": "API"
    }
  ],
  "bureauCode": ["015:11"],
  "programCode": ["015:001"],
  "accessLevel": "public"
}

Changes from v1.1

v1.1 Field Status in v3.0 Action
accessLevel Replaced by accessRights Use a free-text string. The value public remains valid. For restricted datasets write a plain-language explanation.
modified with repeating intervals (e.g., R/P1D) Format no longer valid Set to the actual date the data last changed (e.g., 2024-06-01). Use accrualPeriodicity for update frequency.
temporal as an ISO 8601 string Format no longer valid Use a PeriodOfTime object: {"@type": "PeriodOfTime", "startDate": "2000-01-15", "endDate": "2010-01-15"}
spatial as a plain string or ad-hoc GeoJSON Format no longer valid Use a Location object: {"@type": "Location", "prefLabel": "United States"}
language with RFC 5646 tags (e.g., en-US) Format no longer valid Use two-letter ISO 639-1 codes only (e.g., en, es).
isPartOf Replaced Use inSeries for temporal series membership or hasPart at the parent dataset level for generic collections.
describedByType Absorbed into describedBy Express the format as mediaType within the describedBy Distribution object. No separate field needed.
bureauCode Not in v3.0 core schema Continue populating per existing OMB policy guidance until updated guidance is issued.
programCode Not in v3.0 core schema Continue populating per existing OMB policy guidance until updated guidance is issued.
dataQuality Not in v3.0 core schema Use hasQualityMeasurement for structured quality reporting, or note conformance in scopeNote.

Source: jsonschema/definitions/Dataset.json · Generated reference: jsonschema/docs/Dataset.md