Referenced within the $set-context OperationDefinition in the OperationDefinition.outputProfile element, this profile provides additional constraints on the Parameters resource returned in the response to an invocation of the operation. While the OperationDefinition resource typically allows for sufficient rule definition, FHIR R4 imposes a limitation: Rule: A targetProfile can only be specified for parameters of type Reference or Canonical (i.e., resource-typed parameters cannot be profiled using the OperationDefinition.parameter.targetProfile element). This limitation was addressed in FHIR R5 to accommodate such use cases, but for FHIR R4, the SetContextOutputParameters profile ensures that the resourcesResponse Bundle parameter in the response for $set-context is restricted to Bundles conforming to the SetContextTransactionResponseBundle profile.