http://fhir.patientsknowbest.com/codesystem/observation-category
https://www.hl7.org/fhir/STU3/codesystem.html
There are several different PKB data types which will be represented in FHIR® as Observation resources.
This code set allows these data types to be distinguished.
concept[0]
code = LABORATORY
display = Laboratory
definition = Laboratory
concept[1]
code = MEASUREMENT
display = Measurement
definition = Measurement