The Style Number is the product number assigned by the vendor or manufacturer. If you were ever to return or reorder merchandise, you would need to specify their style number so they know which item you are referring to. If you have reordered a particular item several times, you could have several different SKU numbers for that style — all with the same style number. Some inventory reports show the individual SKU numbers (e.g. you might have three different SKU numbers with one each on-hand) while other reports might just show one line for the style (e.g. showing three on hand.) The style number can be any combination of up to sixteen numbers, letters, spaces and punctuation.