However, your enterprise can also define its own. Each document is assigned a unique number. This number can be assigned internally or externally, depending on the policy of your enterprise. Internal number assignment means that the system assigns the number. External number assignment means that the person creating the document must supply it.
Alphanumeric assignment is only possible in the latter case.
Each document will contain a header and can contain several items. The header contains information relevant to the whole document. The items specify the materials or services to be procured. For example, information about the vendor is contained in the document header, and the material description and quantity to order is specified in each item. The additional data includes additional information about the item, and has no direct connection with the procurement data of the item.