[1] RIF Datatypes and Built-Ins 1.0 (Second Edition) (2017-10-02 19:47:14 +09:00) https://www.w3.org/TR/2013/REC-rif-dtb-20130205/

[2] Assistance requested to be able to register application/rif+xml media type, Ralph Swick, 2021-02-13 06:36:58 +09:00, 2021-02-13T19:20:47.000Z, 2021-03-18T12:13:10.469Z https://lists.w3.org/Archives/Public/public-rdf-dev/2021Feb/0000.html