The item identity element serves to compare items. When doing this, it is only judged if the matter in question is an identical data object of the item type, the contents of the item pictures being not compared. One or more items can be specified. The comparison takes place from the top downwards. The element returns a logic validity flag in case all items are identical. A special case is comparing one item. The item is compared with an empty item, e.g. to test, whether a valid item has been readed from a file. The same effect is attained by comparing with the sheet border.