This code system http://hl7.org/fhir/ingredient-manufacturer-role defines the following codes:

CodeDisplay
allowed Manufacturer is specifically allowed for this ingredient
possible Manufacturer is known to make this ingredient in general
actual Manufacturer actually makes this particular ingredient
<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="The way in which this manufacturer is associated with the ingredient. For example whether it is a possible one (others allowed), or an exclusive authorized one for this ingredient. Note that this is not the manufacturing process role"/><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/ingredient-manufacturer-role"/><content value="complete"/><concept><code value="allowed"/><display value="Manufacturer is specifically allowed for this ingredient"/></concept><concept><code value="possible"/><display value="Manufacturer is known to make this ingredient in general"/></concept><concept><code value="actual"/><display value="Manufacturer actually makes this particular ingredient"/></concept></CodeSystem>