Enterprises should be credited to the bits and pieces

1. Common short form 

UOM = Unit of measurement (https://www.urmc.rochester.edu/purchasing/documents/um.pdf)

PO = Purchase Order

GR/GRN = Good Received/Good Received Note

PI = Purchase Invoice

PR = Purchase Return

SO = Sales Order

DO = Delivery Order

DR = Delivery Return

IV = Invoice

CN = Credit Note

DN = Debit Note