The html source contains the word 'SHALL' but it is not in a text phrase marked as a conformance clause: 'This specification uses the conformance verbs SHALL, MUST, SHOULD, and MAY as defined in RFC 2119. Unlike RFC 2119, however, this specification allows that different applications might not be able to interoperate because of how they use optional features. In particular:'CONFORMANCE_STATEMENT_WORD
This code system is appropriately defined in FHIRPath, it is part of the FHIRPath specification. Will seek a TSMG exemption as part of ballot process
INFORMATION: CodeSystem/calendar-units: CodeSystem: Most code systems defined in HL7 IGs will need to move to THO later during the process. Consider giving this code system a THO URL now (See https://confluence.hl7.org/display/TSMG/Terminology+Play+Book, and/or talk to TSMG) (1 uses)