Thank you for your reply Steve.
1) To answer your first question, I guess I would like to be compliant to RFC7159 and use jsonapi.org to get to that point. So I think I would like my API:s to be compliant with your spec, that depends on - if I have understood everything correctly.
Reading your from jsonapi.org
2) When you say that JSON API is a superset of JSON, then you mean [ disclaimer : not a native English speaker ] that you fulfill the RFC7159 and have one or more extention ?
I see your statement
Unless otherwise noted, objects defined by this specification MUST NOT contain any additional members. Client and server implementations MUST ignore members not recognized by this specification.
so I guess there are no additional members/elements ?
3) is there some kind of relationship between the sites json.org and jsonapi.org ?
Is the purpose of jsonapi.org to help us understand RFC7159
I hope my questions are not to basic, the answers will help me argue for JSON-standard at my workplace.