Open Government Licence

The Open Government Licence is a copyright licence for Crown Copyright works published by the UK government. Other UK public sector bodies may apply it to their publications. It was developed and is maintained by The National Archives. It is compatible with the Creative Commons Attribution (CC-BY) licence.
History.
Since 2001 some works of the UK government had been made available under the Click-Use Licence. This was replaced by the first version of the OGL when it was released on 30 September 2010. The OGL was developed by The National Archives.
The OGL was developed as part of the UK Government Licensing Framework, which also includes a non-commercial Government licence that restricts the commercial use of licensed content, as well as a charged licence for situations where charging for the re-use of content is deemed appropriate.
The first version was designed to work in parallel with other licences such as those released by Creative Commons, mirroring the Creative Commons Attribution (CC-BY) licence and the Open Data Commons Attribution Licence.
Version 2.0, released on 28 June 2013, is directly compatible with the Creative Commons Attribution License 4.0 and the Open Data Commons Attribution License. The OGL symbol (shown above) was also released along with this version, which "at a glance, shows that information can be used and re-used under open licensing".
Version 3.0 was released on 31 October 2014. It is interoperable with Creative Commons' Attribution 4.0 licence, and an OGL-licensed work could be used in a CC-licensed work, however it should be clear that the material used is being used under the OGL and it should still be linked to the OGL.
Licence.
The OGL permits anyone to copy, publish, distribute, transmit and adapt the licensed work, and to exploit it both commercially and non-commercially. In return, the re-user of the licensed work has to acknowledge the source of the work and (if possible) provide a link to the OGL.
The license is also available in machine-readable format.
Applicability.
The OGL applies to many but not all Crown Copyright works. The works must have been expressly released under the OGL terms by the relevant rights owner or authorised information provider. The licence may also be used by other public sector bodies, such as local government, the National Health Service or the police. It may be applied to texts, media, databases and source code.
The OGL includes a list of types of information that it cannot cover. The licence states that it does not apply to:
The Ministry of Defence interpret the "personal data" restriction to mean that photographs where "at least one individual is recognisable" cannot be OGL.
Use.
Use of the OGL is encouraged by the Re-use of Public Sector Information Regulations 2015, regulation 12 of which requires licences to be as non-restrictive as possible.
The OGL is used by organisations at various levels within the UK Government, including:
Open Parliament Licence.
The United Kingdom Parliament uses a similar "Open Parliament Licence" (OPL).