How to refer to licence documents and licence URIs?

Issue

The indication of a licence is recommended for the Catalogue and for Distribution through the use of the dct:license. In addition, the property dct:type with a value from the ADMS licence type vocabulary is recommended for the Licence Document that is the object of the property dct:license. DCAT-AP encourages implementers to use widely recognised licences such as Creative Commons licences, and in particular the CC Zero Public Domain Dedication, the Open Data Commons Public Domain Dedication and License (PDDL), the ISA Open Metadata Licence, the European Union Public Licence (EUPL) and open government licences, such as the UK Open Government Licence. However, it has been noted that more specific advice on how to express a licence document and how to apply the licence type vocabulary for the mentioned licences and for locally defined licences.

Current situation

DCAT-AP implementers apply different practices for describing licences:

• Licences are often referred to using the licence name as a free text field or as a URI;
• Both well-known international licences, such as Creative Commons or Open Data Commons, as well as custom national licences are often used;
• In very few cases, terms and conditions are described as free text; and
• Licence types are not commonly provided.

Recommendation

Rationale

In order to foster the sharing and reuse of government data, it is important for a data provider to clearly specify at which terms and conditions his datasets can be reused. This can be easily done by referring to well-known licences and identifying them using URIs.

Example

The example is based on the Nobel Prize catalogue, which is available via http://www.nobelprize.org/datasets/dcat. Some modifications were made in order to clarify the guideline.

Licence on Catalogue

Licence on Distribution