datos.gob.es conventions

Introduction#

In Spain, the exchange of open data between the Open Data Initiative of the Government of Spain (datos.gob.es) and various data providers, such as regional catalogs, Local Entities, and other organizations, is framed to ensure interoperability and homogeneity of metadata. To achieve this, the European application profile DCAT-AP 2.1.1 will be adapted together with the elements described in the extension DCAT-AP HVD 2.2.0 to incorporate the modeling of the High Value Datasets (High Value Datasets) to national needs, resulting in the standard DCAT-AP-ES, which will be established as a reference for the exchange of metadata on public information at national level.

Since the implementation of the standard, the central portal will only accept metadata in DCAT-AP-ES format. For those providers delivering data directly to the portal, a transitional period will be established following the publication of new versions, allowing systems to adapt to the updated standard using the previous profile of the Technical Standard for Interoperability of Public Sector Information Resources (NTI-RISP).

The conventions guide not only details the specific modifications introduced in the Spanish standard compared to the European version but also defines additional rules to address practical needs. These may include particularities of the Spanish open data context, where implementation might align with distinct technical requirements. Moreover, some of these rules are expected to evolve faster than the main specification, providing greater flexibility and adaptability to technological changes.

This document targets developers and maintainers of open data portals and data providers collaborating with the national catalog. Its purpose is to provide clear guidelines and practical tools for implementing the standard efficiently. However, for specific contexts, the possibility of establishing additional conventions complementing general regulations is left open.

To ensure consistent interpretation, normative terms such as MUST, SHOULD, and MAY are used, as defined in RFC2119, to differentiate mandatory guidelines from optional ones. Although the manual includes diagrams and illustrative examples, these are not normative unless explicitly stated.

This approach aims not only to standardize metadata exchange but also to foster greater harmonization and collaboration among different levels of government in Spain, ensuring robust and scalable interoperability.

Types of Conventions#

Technical Conventions#

These conventions define technical aspects of implementation, including encoding, resource identification, and entity modeling. They are essential for ensuring technical interoperability and correct interpretation of metadata.

Organizational Conventions#

These conventions establish rules for the management and organization of catalogs, data federation, and the identification of organizations. They provide the necessary governance framework for effective metadata management.

Semantic Conventions#

These conventions ensure consistency in the description of resources, guaranteeing that metadata is semantically accurate and consistent.

List of Conventions#

• Convention 01: The publisher's identifier MUST be registered in the Identification of Public Organizations (DIR3) taxonomy.
• Convention 02: The literals dct:title, dct:description, vcard:organization_name, vcard:fn, foaf:name, dcat:keyword and adms:versionNotes MUST be defined with language tags, at least in the spanish language es, and cannot be empty literals.
• Convention 03: Identifiers and URI references SHOULD use the http:// scheme instead of https://.
• Convention 04: Organizations SHOULD implement automatic federation through RDF as the sole method of publishing metadata in DCAT-AP-ES format, avoiding the coexistence of manual and automatic federation for the same organization.
• Convention 05: URIs MUST be correctly encoded at their source, especially when they contain: 1. Reserved characters (?, &, =, #, etc.) 2. Spaces 3. Non-ASCII characters (accents, ñ, etc.) 4. Special characters (<, >, ", {, }, |, \, ^, ~, [, ], `)
• Convention 06: Resources MUST have a unique and persistent identifier that meets the following requirements: 1. Include the dct:identifier property with a unique value for each resource. 2. Maintain identifier consistency even if the resource is updated. 3. Use the same identifier when the resource is published in different catalogs.
• Convention 07: References to legal documents MUST use ELI identifiers when available: 1. For European legislation: http://data.europa.eu/eli/... 2. For national legislation: https://www.boe.es/eli/... 3. For derived documents, use the ELI URI of the main document
• Convention 08: Creation and modification dates of resources MUST meet the following requirements: 1. The modification date (dct:modified) MUST be later than the creation date (dct:created) 2. The modification date MUST reflect the last change in the data, not in the metadata
• Convention 09: A single catalog per publishing organization MUST be used, avoiding the use of subcatalogs through dct:hasPart. Relationships between resources MUST be modeled using the appropriate properties as necessary.
• Convention 10: The catalog MUST include at least the primary sector taxonomy in the dcat:themeTaxonomy property.
• Convention 11: Additional taxonomies may be included to improve dataset classification: http://publications.europa.eu/resource/authority/data-theme or http://inspire.ec.europa.eu/theme
• Convention 12: Datasets categorized as HVD MUST include at least one data service (dcat:DataService) with the following mandatory properties: 1. Endpoint URL (dcat:endpointURL) 2. Endpoint Description (dcat:endpointDescription) 3. Contact Point (dcat:contactPoint) 4. Applicable Legislation (dcatap:applicableLegislation) 5. HVD Category (dcatap:hvdCategory) 6. Documentation (foaf:page) 7. Served Datasets (dcat:servesDataset)
• Convention 13: OGC services SHOULD be modeled as dcat:DataService instead of dcat:Distribution.
• Convention 14: Publisher information SHOULD contain a DIR3 identifier code in the identifier property (dct:identifier), for example: http://datos.gob.es/recurso/sector-publico/org/Organismo/EA0000000
• Convention 15: Creator information SHOULD contain a DIR3 identifier code in the identifier property (dct:identifier), for example: http://datos.gob.es/recurso/sector-publico/org/Organismo/EA0000000
• Convention 16: Geographic coverage MUST be declared using URIs from the NTI-RISP vocabulary for Territories, following these rules: 1. Use the most specific territorial level that corresponds to the dataset's actual scope. 2. Avoid using Spain by default when the scope is narrower. 3. Do not declare a Autonomous Community and its provinces simultaneously. 4. For single-province Autonomous Communities, preferably use the reference to the Autonomous Community.
• Convention 17: When specifying geometric coverage, one of the following formats MUST be used: 1. Using locn:geometry. 2. Using dcat:bbox for the geographic bounding box. 3. Using dcat:centroid for the geographic center (centroid).
• Convention 18: Datasets MUST include at least one contact point (dcat:contactPoint) with the following mandatory properties: - Email address (vcard:hasEmail) - OR Contact URL (vcard:hasURL)
• Convention 19: The contact point SHOULD also include: 1. Name of the area or person (vcard:fn) 2. Telephone number (vcard:hasTelephone) 3. Contact form URL (vcard:hasURL)
• Convention 20: In OGC service distributions, access URLs MUST be modeled as follows: - In dcat:accessURL: Complete URL of the service GetCapabilities request (e.g., http://example.org/wms?request=GetCapabilities&service=WMS) - In dct:conformsTo: URL of the corresponding OGC standard (e.g., http://www.opengeospatial.org/standards/wms)

General conventions#

Organization must have an identifier registered in datos.gob.es taxonomy.#

To ensure the traceability of publishing organizations, they must be registered and available in datos.gob.es taxonomy), either as a DIR3 for a public organization or a private organization whose identifier is the letter P followed by their NIF as a fictitious code (see Annex 3. Mapping of Organizational Identifiers).

Indicating Spanish language in declarations#

Literal fields with multilingual xml:lang tags must be at least in Spanish (es).

Using HTTP URIs#

To maintain compatibility and avoid interoperability issues, it is recommended to use HTTP URIs instead of HTTPS in identifiers and references. HTTP URIs are equally dereferencable as HTTPS through redirection.

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@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix dct: <http://purl.org/dc/terms/> .

# ✅ Uso recomendado general con HTTP
<http://datos.gob.es/catalogo/dataset/001>
    a dcat:Dataset ;
    dct:publisher <http://datos.gob.es/recurso/sector-publico/org/Organismo/EA0000000> ;
    dcat:theme <http://publications.europa.eu/resource/authority/data-theme/TECH> .

# ✅ Excepción para ELIs del BOE
<http://datos.gob.es/catalogo/dataset/002>
    a dcat:Dataset ;
    dct:publisher <http://datos.gob.es/recurso/sector-publico/org/Organismo/EA0000000> ;
    dcatap:applicableLegislation <https://www.boe.es/eli/es/rdlg/2001/07/20/1> .

# ❌ Uso no recomendado con HTTPS
<https://datos.gob.es/catalogo/dataset/001>
    a dcat:Dataset ;
    dct:publisher <https://datos.gob.es/recurso/sector-publico/org/Organismo/EA0000000> ;
    dcat:theme <https://publications.europa.eu/resource/authority/data-theme/TECH> .

Automatic Data Federation#

To ensure consistency and quality of metadata, as well as to simplify the federation process, the exclusive use of automatic federation through RDF (DCAT-AP-ES) is established as the sole method for data ingestion into the portal.

URI Encoding#

To ensure RDF validity and avoid processing issues, all URIs must be correctly encoded according to RFC 3986.

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 @prefix dcat: <http://www.w3.org/ns/dcat#> .

# ✅ URI correctamente codificada
<https%3A%2F%2Fwww.ine.es%2Fdyngs%2FINEbase%2Foperacion.htm%3Fc%3DEstadistica_C%26menu%3Dresultados> 
    a dcat:Dataset .

# ❌ URI sin codificar (incorrecto)
<https://www.ine.es/dyngs/INEbase/operacion.htm?c=Estadistica_C&menu=resultados> 
    a dcat:Dataset .

Unique and Persistent Identifiers#

To ensure the correct identification and traceability of resources over time, as well as to avoid duplicates during federation from multiple sources, it is necessary to establish a system of unique and persistent identifiers since the identifier (dct:identifier) is the property that allows the unique and unequivocal identification of the dataset.

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@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix dct: <http://purl.org/dc/terms/> .

# Dataset en el catálogo de datos abiertos 
<http://datos.comunidad.es/dataset/medioambiente/calidad-aire-2024>
    a dcat:Dataset ;
    dct:identifier "MA-AIRE-2024" ;
    dct:title "Calidad del aire 2024"@es .

# El mismo dataset en el catálogo CSW (conforme a GeoDCAT-AP)
<https://ide.comunidad.es/catalogo/dataset/calidad-aire-2024> 
    a dcat:Dataset ;
    dct:identifier "MA-AIRE-2024" ;
    dct:title "Calidad del aire 2024"@es .

ELI Identifiers for Legal Documents#

To ensure a unique and persistent reference to legal documents, the European Legislation Identifier (ELI) must be used as the standard URI.

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@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix dct: <http://purl.org/dc/terms/> .
@prefix dcatap: <http://data.europa.eu/r5r/> .

# Referencia a legislación comunitaria (UE)
<http://example.org/dataset/1> a dcat:Dataset ;
    dcatap:applicableLegislation <http://data.europa.eu/eli/reg_impl/2023/138/oj> ;
    dct:conformsTo <http://data.europa.eu/eli/dir/2007/2/2021-06-27> .
    ...

# Referencia a legislación nacional (España)
<http://example.org/dataset/2> a dcat:Dataset ;
    dct:conformsTo <https://www.boe.es/eli/es/l/2007/12/16/37/con> .
    ...

Managing Creation and Modification Dates#

To ensure the temporal traceability of resources and their correct tracking, it is important to properly manage creation and modification dates.

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@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix dct: <http://purl.org/dc/terms/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

# Ejemplo de gestión correcta de fechas
<http://example.org/dataset/1> a dcat:Dataset ;
    dct:title "Dataset ejemplo"@es ;
    dct:created "2025-01-01"^^xsd:date ;
    dct:modified "2025-01-30"^^xsd:date .

# Ejemplo con precisión horaria
<http://example.org/dataset/2> a dcat:Dataset ;
    dct:title "Dataset con hora"@es ;
    dct:created "2025-01-01T10:00:00Z"^^xsd:dateTime ;
    dct:modified "2025-01-30T15:30:00Z"^^xsd:dateTime .