PHPCMS V9{loop subcat(0,0,0,$siteid) $r}怎么解释？

{loop subcat(0,0,0,$siteid) $r}{/loop}

/**

* 获取子栏目 
* @param $parentid 父级id  
* @param $type 栏目类型 
* @param $self 是否包括本身 0为不包括 
* @param $siteid 网站id 
*/ 
function subcat($parentid = NULL, $type = NULL,$self = '0', $siteid = '') { 
        if (empty($siteid)) $siteid = get_siteid(); 
        $category = getcache('category_content_'.$siteid,'commons'); 
        foreach($category as $id=>$cat) { 
                if($cat['siteid'] == $siteid && ($parentid === NULL || $cat['parentid'] == $parentid) && ($type === NULL || $cat['type'] == $type)) $subcat[$id] = $cat; 
                if($self == 1 && $cat['catid'] == $parentid && !$cat['child'])  $subcat[$id] = $cat; 
        } 
        return $subcat; 
}