Existing Wording: Observation.dataAbsentReason - "Null" or exceptional values can be represented two ways in FHIR

Observations. One way is to simply include them in the value set and

represent the exceptions in the value. For example, measurement values for

a serology test could be "detected", "not detected", "inconclusive", or "test

not done". The alternate way is to use the value element for actual

observations and use the explicit dataAbsentReason element to record

exceptional values. For example, the dataAbsentReason code "error" could be

used when the measurement was not completed. Because of these options,

use-case agreements are required to interpret general observations for

exceptional values.

Comment:

test not done was reported as part of the status in V2. Would make sense to stay with that both for continuity and because it is NOT really an answer