The child-most action(s) defined by an OrderTemplate are internal references to a RegimenEntryTemplate (a profile of the ActivityDefinition resource at http://hl7.org/fhir/activitydefinition.html). The RegimenEntryTemplate defines a single medication and its dosage instructions. Because a RegimenEntryTemplate is so dependent on the OrderTemplate from which it comes, it is defined as an internal or contained resource within the OrderTemplate. Please see http://hl7.org/fhir/plandefinition.html for more information regarding the relationship between PlanDefinition and ActivityDefinition, and please see https://www.hl7.org/fhir/references.html for more information on contained resources. Note that the RegimenEntryTemplate is of kind (ActivityDefinition.kind) MedicationRequest (see http://hl7.org/fhir/medicationrequest.html).