private function extractDiscussionTypes(array $FormPostValues)
	{
		$types = [];
		foreach (array_keys($FormPostValues) as $key) {
			$matches = [];
			if (preg_match('/^DiscussionType_(\w+)_.+$/', $key, $matches)) {
				$types[] = $matches[1];
			}
		}

		return array_unique($types);
	}