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Technical Team/Proposals/2010-10-21/Composite licensing

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Read-only copy of the SPDX wiki. The wiki is no longer active; its content has moved to https://github.com/spdx. Last edited 2013-03-07 by MartinMichlmayr.

Status: draft

Issue

There are some licensing scenarios which are not expressable in SPDX. For example, there is currently no way to express that a file can be used under the licenses A and B or A and C.

Use cases

The set of use cases we need to be able to describe in SPDX is:

  1. a single license
  2. choice of one from multiple single licenses
  3. multiple licenses (conjunctive)
  4. choice of one from multiple conjunctive license sets

Proposal

Introduce a license set concept to cover all these use cases. Specifically, a `ConjunctiveLicenseSet` and a `DisjunctiveLicenseSet`. Members of these types of sets would be of type `License`, `ConjunctiveLicenseSet` or `DisjunctiveLicenseSet`. This would allow composing licensing information in arbitrary conjunctive and disjunctive groupings.

The definition of `License` would not change. The `DeclaredLicense` and `DetectedLicense` properties would be updated to allow their value to be a `License`, `ConjunctiveLicenseSet`, or `DisjunctiveLicenseSet`.

Examples

Single license





Disjunctive licenses










Complex disjunctive licenses




















Changes

These changes are available in the 'composite-licensing' branch of https://github.com/pezra/spdx-spec.git. A full version of the spec with these changes is attached, as is a patch file to implement these changes.

Attachments

Categories: Technical