code: protected function addReceivedFrom($explicitRf, $doAutoAdd, $defaultRf, &$tattooCounter)
      {
          if ($this->dataElementsMaster === null) {
              $this->dataElementsMaster = new DataElementsMaster();
          }
  
          if (!empty($explicitRf) || ($doAutoAdd && !empty($defaultRf))) {
              //Set a received from if explicitly provided or if auto received from is enabled
  
              $tattooCounter++;
  
              $rfToAdd = (!empty($explicitRf)) ? $explicitRf : $defaultRf;
  
              $this->dataElementsMaster->dataElementsIndiv[] = $this->createElement(
                  new ReceivedFrom(['receivedFrom' => $rfToAdd]),
                  $tattooCounter
              );
          }
      }
docs: Add Received From field - if needed.
  
  @param string|null $explicitRf Explicitly provided RF string on request.
  @param bool $doAutoAdd Wether to automatically add an RF field.
  @param string|null $defaultRf The default RF string set in the client.
  @param int $tattooCounter (BYREF)
  @throws \ReflectionException