CUserTypeManager::deleteUserFieldValuesByEvent

protected function deleteUserFieldValuesByEvent(string $entityId, int $id): ?bool
{
	$result = null;

	$event = new BitrixMainEvent('main', 'onDeleteUserFieldValues', ['entityId' => $entityId, 'id' => $id]);
	$event->send();
	foreach($event->getResults() as $eventResult)
	{
		if($eventResult->getType() === BitrixMainEventResult::SUCCESS)
		{
			$result = true;
		}
		elseif($eventResult->getType() === BitrixMainEventResult::ERROR)
		{
			$result = false;
		}
	}

	return $result;
}