This code system http://hl7.org/fhir/price-component-type defines the following codes:

Code Display Definition
base base price the amount is the base price used for calculating the total price before applying surcharges, discount or taxes.
surcharge surcharge the amount is a surcharge applied on the base price.
deduction deduction the amount is a deduction applied on the base price.
discount discount the amount is a discount applied on the base price.
tax tax the amount is the tax component of the total price.
informational informational the amount is of informational character, it has not been applied in the calculation of the total price.
<status value="draft"/> <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="Codes indicating the kind of the price component."/> <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/price-component-type"/> <content value="complete"/> <concept> <code value="base"/> <display value="base price"/> <definition value="the amount is the base price used for calculating the total price before applying surcharges, discount or taxes."/> </concept> <concept> <code value="surcharge"/> <display value="surcharge"/> <definition value="the amount is a surcharge applied on the base price."/> </concept> <concept> <code value="deduction"/> <display value="deduction"/> <definition value="the amount is a deduction applied on the base price."/> </concept> <concept> <code value="discount"/> <display value="discount"/> <definition value="the amount is a discount applied on the base price."/> </concept> <concept> <code value="tax"/> <display value="tax"/> <definition value="the amount is the tax component of the total price."/> </concept> <concept> <code value="informational"/> <display value="informational"/> <definition value="the amount is of informational character, it has not been applied in the calculation of the total price."/> </concept> </CodeSystem>