您可以在上筛选这些关键字的查询\'query\'. 我会尽可能晚地启动过滤器，以避免副作用。

示例代码，tested:

add_filter( \'postmeta_form_limit\', \'wpse_73543_hide_meta_start\' );

function wpse_73543_hide_meta_start( $num )
{
    add_filter( \'query\', \'wpse_73543_hide_meta_filter\' );

    return $num;
}

function wpse_73543_hide_meta_filter( $query )
{
    // Protect further queries.
    remove_filter( current_filter(), __FUNCTION__ );

    $forbidden = array ( \'the\', \'keys\', \'you\', \'want\', \'to\', \'hide\' );
    $where     = "WHERE meta_key NOT IN(\'" . join( "\', \'", $forbidden ) . "\') ";
    $find      = "GROUP BY";
    $query     = str_replace( $find, "$where\\n$find", $query );

    return $query;
}