Endpoint.period MS constraint

[IrfanH99]

Section: In the IHE mCSD iGuide version 3.8.0, Enpoint Profile

Issue: The pan-Canadian Care Services Directory (based on the mCSD) received pushback from vendors currently implementing endpoint on the use of the .period element and the strong mustSupport requirement placed on it. Through our discussion with the vendors, we learned that the use cases for this element are very niche and majority of the vendors do not see using it at all. With further discussions with IHE ITI WG members, we did not find its use to be major at an international level.

Proposed Change: A relaxation of the mustSupport constraint on this element is proposed.

Priority: Medium

[JohnMoehrke]

Given that IHE uses "required if known" as our definition of MS. What is the concern? If you never have data to populate the element, then the implementation is indistinguishable from one in which the element is not tagged with MS.
Can you explain the negative you see with the current specification?