[amcd]

in the showthread_query hook, we have

$alluserawards =  $db->query_read(" 
            SELECT a.*, au.*, post.userid, post.postid  
            FROM " . TABLE_PREFIX . "post AS post 
            INNER JOIN " . TABLE_PREFIX . "award_user AS au ON (au.userid=post.userid) 
            INNER JOIN " . TABLE_PREFIX . "award AS a ON (a.award_id=au.award_id) 
            WHERE $postids 
". iif((!empty($cache_postids)), "post.postid IN (" . $cache_postids . ")") ." 
            GROUP BY au.issue_id 
            $awardsdisplayorder 
        "); 

what is the purpose of that 'group by'?