BlockA
         item1
         item2
         item3
         item4
    BlockB
         item5
         item6

   cur_blk := :System.Current_Block;
   f_item := Get_block_property(cur_blk,First_item);
   l_item := Get_block_property(cur_blk,Last_item);

DECLARE
  itm  VARCHAR2(100);
BEGIN
  itm := Get_block_property('Data block name in quotes',first_item);
  
  LOOP
    EXIT WHEN itm IS NULL;
    itm := blk||'.'||itm;
    Message('itm'||' is a '||Get_item_property(itm,item_type));
    itm := Get_item_property(itm,nextitem);
  END LOOP;
END;