Clarification on the purpose of the API license?

In the Swagger 2.0 specification, there is support for adding a License as one of the informational fields and the description for this is License information for the exposed API.

This seems a bit ambiguous, since a license could potentially be understood to apply to one or more of the following contexts:

1. Use of the API. This situation seems to be already handled by the termsOfService section though.
2. Data retrieved from the API
3. The specification JSON/YAML for the API indeed, there is a license for the Swagger 2 specification
4. Client/server code generated via swagger-codegen could some licenses theoretically extend to that?

I am guessing that the item 3 is the intended use for the license field, but I will admit that at first I thought it was meant for the first case and I could not see how a license would actually apply. Is it possible to get some clarification of how licenses should be picked here and where they do and do not apply?