Having a Create Commons CC BY NC SA license associated with an OpenAPI using the info licensing property ensures that the legal aspects of licensing the API always travel with the technical contract for an API
OpenAPI Info License Identifier Cc By Nc Sa Error
Message: Info MUST Have CC-BY-NC-SA 4.0 License
Policies
License for APIs
Including a license in your OpenAPI info section makes the legal terms explicit. I see way too many APIs where consumers have no idea what they are legally allowed to do.