license definition in schema.org context document

What is the intended meaning of the term "license" in the context of a schema.org description serialized as json-ld? The term is defined twice in https://schema.org/docs/jsonldcontext.json (also if you retrieve context document from http://schema.org or https://schema.org using content negotiation). 

 

Lines 22-25:

...

        "ical": "http://www.w3.org/2002/12/cal/icaltzd#",

        "license": "http://www.w3.org/1999/xhtml/vocab#license",

        "ma": "http://www.w3.org/ns/ma-ont#", 

...

 

Lines 1748-50

...

        "letterer": { "@id": "schema:letterer"},

        "license": { "@id": "schema:license", "@type": "@id"},

        "line": { "@id": "schema:line"},

...

 

Since the schema:license definition appears later in the context document, I assume it wins over the definition linking to the xhtml vocabulary, but perhaps it would be a good idea to clean this up in the schema.org context document? Unless this is unavoidable in how context document is being generated. So in my json-ld I would use the key "license" to refer to schema:license property and the key "xhv:license" to refer to license property as defined in xhtml vocabulary? (Semantic difference is minimal, so I'm probably being pedantic.)

 

Note, there are a number of other duplicated keys in the schema.org context document besides license, but none of them are contradictory (and so less chance of misinterpretation). E.g., the definition of the prefix "org" (lines 27 & 28) and the definitions of many terms from the Health and Life Sciences Extension (health-lifesci) such as  Nursing (lines 684-85), SurgicalProcedure (lines 979-980), etc. Less of a concern, but would it be possible to clean these up since (if I'm remembering correctly) duplicated keys violate a SHOULD in the JSON standard and some parsers object to duplicated keys? 

 

Apologies if this issue has already been addressed in an earlier post to this list that I failed to find or is already dealt with in pending release. 

 

Thanks, 

 

Tim Cole

University of Illinois at Urbana-Champaign