Open License

An open license is a legal grant that lets anyone use, redistribute, modify, separate, and combine a work, for any purpose and without a fee, subject only to conditions that the Open Definition accepts. The license text, not the label on a portal, decides whether the rights condition is met; the Open Definition also requires access to the whole work, machine readability, and an open format before data counts as open.

Required permissions and acceptable conditions

Under the Open Definition, an open license must permit use, redistribution, modification, separation of parts, and compilation with other works; it must not discriminate against persons or fields of endeavor; its rights must propagate to everyone who receives the work; and it must not charge. It may require attribution, may require modified versions to be marked, may require derived works to be shared under the same terms (share-alike), and may require notices to be kept.

Conditions that limit the field of use are different. “Research only,” “non-commercial,” or “government use only” may be perfectly reasonable choices for a data holder, but a license carrying them does not make the data open in this sense. Read both lists before calling a dataset open, and distinguish a condition you must satisfy, such as crediting the source, from a limit on what you may do with the data.

A license is not a release decision

Choosing a license comes after deciding that the data may be released to everyone. A fictional transit operator can attach an attribution license to its timetable but should not distribute per-card trip records under a public open license, because those records are not suitable for public release; sharing them with a university under a restricted agreement is a different arrangement with its own terms. Once open copies exist they cannot be recalled, so the release decision, the privacy assessment, and the license choice are three steps, not one.

Record which license and version each published file carries, and keep it with the data, so that reusers know their rights and the operator knows what it promised.

Examples here are illustrative and are not legal advice.

References

• Open Definition 2.1