FHIR version 4 introduced a new pattern in which various participations that were previously named (e.g., recorder, data enterer), are now handled using a Participation class with a role code (e.g., recorder, data enterer) and a pointer to the Actor which is participating in the role of the role code. This actor may be any on of a number of entities, such as a Patient, Practitioner, Organization, PractitionerRole, Device, RelatedPerson, etc. This approach is analogous to the FHIM Participation class, except that in the past, FHIM has used named properties in the clinical classes (e.g., performer, observer), which then pointed to Attribution or directly to participation, depending on whether additional data such as the date recorded, location, or digital signature were typically needed. The FHIM use of Attribution was driven in part by alignment with CIMI. As FHIR adopted some patterns from CIMI, but not others, the FHIM may well use this FHIR pattern in the future over the CIMI Attribution pattern. If so, this would require changing all clinical classes that currently reference named participations (e.g., performer, observer), to reference a bag of participations instead – with said bag being perhaps restricted by the role types allowed, or even the types of actors that may be allowed. It is possible that we may wish to adopt a middle-ground approach, were named properties are derived attributes that may be implemented using the bag of participations approach. Since this is a fundamental design decision, future versions of the FHIM will likely have to make a dogmatic statement concerning the appropriate approach. For now, however, we allow both approaches to intermix, even though they are fundamentally duplicative. "Indicates who or what performed or participated in the charged service." - HL7 FHIR, Invoice.participant