[dxwg] Should any DCAT predicates be registered as IANA relations? (#946)

dr-shorthair has just created a new issue for https://github.com/w3c/dxwg:

== Should any DCAT predicates be registered as IANA relations? ==
From time to time elements/properties/predicates from W3C vocabularies are also registered with IANA in one place or another. e.g. 
- two media-types and one relation from POWDER https://www.w3.org/TR/powder-dr/#appB
- four relations in Resource Hints (in progress) https://www.w3.org/TR/resource-hints/#iana-considerations
- 15 interval relations from OWL-Time - see https://github.com/link-relations/registry/issues/4 

Life is easier if they are identified in advance and a specific IANA Considerations annex added to the Rec in good time. 

Is there anything in DCAT that might be useful in IANA? 

Please view or discuss this issue at https://github.com/w3c/dxwg/issues/946 using your GitHub account