This code system http://hl7.org/fhir/substance-optical-activity defines the following codes:

CodeDisplay
+ dextrorotary
- levorotary
<status value="active"/><experimental value="false"/><date value="2021-01-05T10:01:24+11:00"/><publisher value="HL7 (FHIR Project)"/><contact><telecom><system value="url"/><value value="http://hl7.org/fhir"/></telecom><telecom><system value="email"/><value value="fhir@lists.hl7.org"/></telecom></contact><description value="The optical rotation type of a substance."/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/substance-optical-activity"/><content value="complete"/><concept><code value="+"/><display value="dextrorotary"/></concept><concept><code value="-"/><display value="levorotary"/></concept></CodeSystem>