Discussion: rcn = semantic-content should be default for semantic queries
This could be related to issue #158.
In TS-0001, table 8.1.2-1, the result content type "semantic-content" is defined when the RETRIEVE request is actually a semantic query. This is indicated by the semanticQueryIndicator (sqi) request attribute set to True in the request. In this case the rcn actually must be set to "semantic-content" because this is the only possible content in the response. Otherwise an error is returned.
In discussions with developers that work with semantic queries it was suggested that in case a RETRIEVE request is a semantic query (i.e. the sqi request attribute is set to True) the rcn, if not present in the request, should default to "semantic-content".
This could be done by updating the description of "semantic-content":
semantic-content: Representation of semantic information that is the result of a semantic query as indicated by the setting of the Semantic Query Indicator parameter.
This shall be only valid and the default for a Retrieve operation with Semantic Query Indicator parameter set.
and adding a "(Note)" to the "Valid" cell in the table row for "semantic-content".
Also note that the ETSI specification ETSI TS 103 780 (SmartM2M; SAREF: oneM2M usage guidelines) at:
https://www.etsi.org/deliver/etsi_ts/103700_103799/103780/01.01.01_60/ts_103780v010101p.pdf
has a (currently wrong) example in section 8.3.3. That example doesn't specify the rcn.