URIs

Definition

Uniform resource identifiers (URIs) are unique identifiers that are used to reference information published on the web that will still be valid in the future.

URIs can identify anything, including the following.

Web documents. URIs are used to identify anything on the web, such as web pages, PDFs, Word files, Excel files, XML files, images, etc.

Real-world objects. ‘URIs identify not just Web documents, but also real-world objects like people and cars, and even abstract ideas’ – World Wide Web Consortium, ‘URIs for Real-World Objects’.

Persistent URI service

EU institutions may request persistent HTTP URIs for high-value applications and data sets on the data.europa.eu subdomain. The main objective of the service is to support and maintain URIs in the long term.

There are three key aspects to the service.

1. Governance. Deciding if an EU institution can be granted a namespace is handled at the central level, but identification and persistence are managed at the local level.
2. A common pattern for URIs. This is established on the data.europa.eu subdomain.
3. A central URI redirection service This registers and manages the persistent URI namespace and forwards the HTTP requests.

URIs in Publications Office websites

Publications Office Portal

URIs on the Publications Office Portal are mainly used for data sets.

Examples:

EuroVoc: http://eurovoc.europa.eu/438855

Corporate body authority table: http://publications.europa.eu/resource/authority/corporate-body/EP

DET (external data set): http://data.europa.eu/uxp/det

EuroSciVoc (CORDIS): http://data.europa.eu/8mn/euroscivoc/40c0f173-baa3-48a3-9fe6-d6e8fb366a00

EuroVoc on ODP: http://data.europa.eu/88u/dataset/eurovoc

Each of these URIs identifies a specific element in the data: a concept, a concept scheme, a data set, etc. This identifier can be used to retrieve the data from the SPARQL endpoint of the Publications Office, which is called ‘CELLAR’ (http://publications.europa.eu/webapi/rdf/sparql).

European legislation identifier (on EUR-Lex)

The European legislation identifier (ELI) uses HTTP URIs to identify all online legal information officially published across the EU. URIs are described using URI templates.

ELI URI template:
http://data.europa.eu/eli/{typedoc}/{year}/{naturalnumber}/oj

Example of an existing URI:
http://data.europa.eu/eli/dir/2000/60/oj

More information regarding ELI URIs can be found at: https://eur-lex.europa.eu/eli-register/eu_publications_office.html