A License describes of the copyright under which the content is protected and the means to check its provisions and/or limitations.

    "identifier": "CC-BY-NC-ND-4.0",
    "ref": "",
    "meta" : {
      "property": "value"
Property Description Type Required
identifier Sluggable label of the copyright schema. string Yes
meta Arbitrary object of custom properties. object No
ref Internet reference for the full definition of the copyright terms. object Yes


A valid license is any identifier from the SPDX list: