"I once worked at an electronic component distributor where the IT "guru" wrote an inventory control program in RPG II that lacked units of measure. So when you saw that you had 647 of something you had no idea if it was pieces, feet, spools, gallons, pallets or some other weird measure."
We used to have similar fun ordering stationery... you would order 10 foolscap folders and would receive 10, 10 packs (of 5) or 10 boxes (of 100), depending on what happened to be in front of the person picking your order... 10 ordered, 10 picked, job done. Writing '10 boxes' on an order would not guarantee the correct amount, even where a form had a UOI (unit of issue) box