Healthcare use of Identity level of assurance

There is discussion going on in the FHIR chat on this topic. I wanted to capture details as it seems that most of the problem is getting everyone understanding the same thing. The discussion is specific to an open system for recording and showing that an individual has received a COVID-19 immunization. (see HL7 effort on vaccination credentials and  broader outreach). There are other COVID-19 immunization trancing efforts, the above just is the one I am most closely working with. ...