In 2010, the Sunlight Foundation defined ten principles for the openness of government data and updated them in 2014.
All public data will be made available. Public data is data that is subject to unauthorised data protection, security or access restrictions.
The data is collected at its origin. This is done with the highest possible degree of granularity, not in aggregated or otherwise modified formats.
Data is made available as quickly as necessary to maintain value.
Ease of physical and electronic access
Data will be made available to as many users as possible for as many purposes as possible.
Data is made available in a structured form for automated processing.
Data are available to all without prior registration of users.
Use of commonly owned standards
Data shall be provided in standardised formats over which no legal person has sole control.
Data is not subject to copyright, patents, trademarks or trade secrets. Sensible data protection, security and access restrictions are permitted.
Data are made available permanently, if necessary on the basis of a suitable versioning, i.e. a marking of the data that they correspond only to a certain state.
Usage costs should not be an obstacle. They should therefore be kept to a minimum or, whenever possible, free access to the data should be provided.