This case-sensitive code system http://hl7.org/fhir/us/cdmh/CodeSystem/pcornet-death-confidence-codes defines the following codes:

Code	Display	Definition
E	Excellent	Death Cause or Match Confidence is Excellent
F	Fair	Death Cause or Match Confidence is Fair.
P	Poor	Death Cause or Match Confidence is Poor.
NI	No information	Death Cause or Match Confidence has No information.
UN	Unknown	Death Cause or Match Confidence is Unknown.
OT	Other	Death Cause or Match Confidence is Other.