CCrmProductFile::CheckFieldId

static function CheckFieldId($catalogID, $fieldID)
{
	if ($fieldID === "DETAIL_PICTURE")
		return true;
	elseif ($fieldID === "PREVIEW_PICTURE")
		return true;
	elseif ($fieldID === "PICTURE")
		return true;
	elseif ($catalogID <= 0 || $catalogID !== CCrmCatalog::EnsureDefaultExists())
		return false;
	elseif (!preg_match("/^PROPERTY_(.+)\$/", $fieldID, $match))
		return false;
	else
	{
		$db_prop = CIBlockProperty::GetPropertyArray($match[1], $catalogID);
		if(is_array($db_prop) && $db_prop["PROPERTY_TYPE"] === "F")
			return true;
	}
	return false;
}