This code system http://hl7.org/fhir/v2/0174 defines the following codes:

CodeDisplayComments
AAtomic service/test/observation (test code or treatment code)can be associated with one or more OM4 (specimen) segments<p>a single direct observation and would usually be associated with an OM2 and/or OM3 segments
CSingle observation calculated via a rule or formula from other independent observations (e.g. Alveolar-arterial ratio, cardiac output)can be associated with one or more OM4 (specimen) segments<p>a derived quantity and would usually be associated with an OM6 segment
FFunctional procedure that may consist of one or more interrelated measures (e.g. glucose tolerance test, creatinine clearance), usually done at different times and/or on different specimenscan be associated with one or more OM4 (specimen) segments<p>See comment for value S
PProfile or battery consisting of many independent atomic observations (e.g. SMA12, electrolytes), usually done at one instrument on one specimencan be associated with one or more OM4 (specimen) segments<p>See comment for value S
SSuperset-a set of batteries or procedures ordered under a single code unit but processed as separate batteries (e.g. routines = CBC, UA, electrolytes)<p>This set indicates that the code being described is used to order multiple service/test/observation bcan be associated with one or more OM4 (specimen) segments<p>Codes P, F, and S identify sets (batteries) and should be associated with an OM5 segment that defines the list of elements. The definitions for the contained elements would have to be sent in o

Additional Language Displays

Codedenl
AEinzeluntersuchungAtomische service/test/observatie (testcode of behandelingcode)
CBerechnetes EinzelergebnisEnkelvoudige observatie berekend via regels of formule uit andere onafhankelijke observaties (bijv. Alveolair--arteriële gradiënt, hart-minuut-volume)
FFunktionstestFunctionele behandeling die kan bestaan uit een of meer gerelateerde metingen (bijv. glucosetolerantietest, creatinineklaring), meestal uitgevoerd op verschillende momenten en/of verschillende monsters
PBatterieanordnungProfiel of battery bestaande uit vele onafhankelijke atomische observaties (bijv. SMA12, electrolyten), meestal met één instrument op één monster
SLatte von mehreren Batterieanforderungen (Aufnahmelatte)Superset--een set batteries of procedures aangevraagd onder een enkele aanvraagcode maar behandeld als afzonderlijke batteries (bijv. routines = CBC, UA, electrolyten); Deze set geeft aan dat de bedoelde code wordt gebruikt voor het aanvragen van meerdere services/tests/observaties