I think I was not clear. For each item each time we buy it we usually have 3 purchase invoices. One for the item itself from the supplier, one for tranport costs, one for import duties. The latter last two are always 0 in quantity as we allocate to a specific item (whether we buy 1, 10, 100 pcs.) the total cost of transport and import duties, and Manager redistributes automatically that cost to the each unit of the item.
As you can see, the last line where the blue arrow points at has no indication of the item, the supplier (Contact) etc. It only shows the date (the same of the line above from RRA) and the quantity 0.
But this line does not appear in many other items when I go and check the transaction list. See here:
It is not clear to me why this additional line appears, and how I can remove it.
And yes, you are right @Tut, this is the list of transactions affecting the quantity on hand of a specific item.