The standard for exchanging data sets.

Everything about our DCAT standard

In order to present data sets in a well organised manner and to be able to search for data sets in a targeted manner, data sets on data.overheid.nl are described with metadata. The W3C has developed DCAT for this, a metadata standard for the description of data sets. Read more about DCAT by W3C.

DCAT standard European Union

The European Union has drawn up a DCAT application profile. The Dutch DCAT application profile is based on version 1.1 of the EU profile (more about DCAT-AP-EU 1.1 of the EU). An update of the DCAT-AP-EU is continuously underway. This includes mapping to ISO 19115, the metadata standard for geo data sets, among other things. Follow the developments of DCAT-AP-EU.

DCAT standard for the Dutch government: DCAT-DONL

The Dutch government has translated the DCAT-AP-EU into a Dutch application profile. The application profile for data sets is the specification of the metadata that the Dutch government uses for the exchange of metadata about datas ets between data catalogs. Data.overheid.nl is set up on the basis of DCAT-DONL. The application profile consists of a description of the data model, the value lists that are used to fill in the model and the way of exchanging information about data sets. The Dutch government has more application profiles (also called IPMs) for the exchange of other types of government information.

A new version of the data portal went live at the beginning of 2015, based on a new version of CKAN. The new portal is built according to DCAT-DONL. Full compatibility with the European DCAT standard has been achieved for Dutch data sets. A mapping has also been made to ISO 19115, the metadata standard for geo data sets used by the National GeoRegister (NGR). This allows us to raise the quality of the metadata exchange with other data catalogs in the Netherlands and Europe to a higher level.

Why DCAT for data sets?

Why use a Dutch application profile of DCAT? The application profile for data sets describes which information we exchange between Dutch data catalogs and which referential data we use for this. Because we limit ourselves to Dutch data catalogs, we can make agreements about the referential data to be used, such as identification of organisations, subject and theme classification. Some of these referential data are available as value lists (see DCAT-AP-DONL value lists) and are based on the standard OWMS value lists.

DCAT-DONL

DCAT-DONL is intended to keep the exchange of metadata within the Netherlands simple. If Dutch Data Catalogs supply their metadata according to the application profile to data.overheid.nl, data.overheid.nl can then pass it on to the European data portal. In 2017 the documentation of a new version of DCAT was started, based on the new version DCAT-AP-EU 1.1. This has resulted in a documented DCAT standard DCAT-AP-DONL 1.1 (documentation: DCAT-AP-DONL 1.1).

DCAT-AP-DONL 1.1 

Data.overheid.nl has drawn up the government profile for DCAT in collaboration with various parties. Its formal name is DCAT-AP-DONL 1.1. This version of DCAT is currently used on data.overheid.nl for the supply of data set metadata by other governments and external suppliers. Data.overheid.nl then delivers to the European data portal in DCAT format.

For all documentation and information about the special government profile for the exchange of metadata, please refer to the following page:

DCAT-AP-DONL 1.1 (Specification and Documentation)

DCAT-AP-DONL value lists (updated until June 2020; in Dutch)

Advice on using DCAT

Data.overheid.nl gives the following advice on the use of the DCAT standard:

1. DCAT-DONL mandatory: for supplying metadata about data sets of the Dutch government to data.overheid.nl

2. DCAT-DONL desirable: for the exchange of metadata about data sets between Dutch governments and their suppliers

3. DCAT-EU mandatory: for supplying metadata to the EU data portal (only for data.overheid.nl)

4. DCAT-EU desirable: for all public and private parties in the EU that exchange data set information that does not concern data from the Dutch government.

5. DCAT (W3C) desirable: for all public and private parties worldwide that exchange data set information that does not concern data from the Dutch government.

Parties are also free to create derived application profiles from the already published application profiles of the EU and data.overheid.nl, ideally publishing a mapping to the leading profiles.

DCAT 2.0

From February 2020, a new version of DCAT has been developed by the W3C. On June 29, 2020, the European Union published its version 2.0.1 of an application profile for this version of DCAT . This means that data.overheid.nl can get to work to upgrade the DCAT-DONL to version 2.0. We will provide more information on this page as soon as a schedule is available.

More information