REST API Documentation: schema lacks definitions

I’m finding a few uses of the REST API to be challenging. In part, this is due to some pretty scant documentation: while the docs are pretty good about showing a given API Schema, there’s no definition that explains just what each of those fields are.

Example: In the Sprint API, there’s a field called “originBoardId”. When creating a sprint, this field would contain the ID of the Board that originated the sprint. Great.

But when querying a Board’s sprints, sometimes the returned “originBoardId” value disagrees with the board ID that you asked for. How? Does “origin” mean “The board this sprint belongs to”, or “The board this sprint originally belonged to?” How can those two be different if there’s no mechanism in Jira to move a sprint from one board to another?

Either way, the meaning of each field in the schema should be documented… and, at present, they aren’t (at least that I can find).