The reference method is a document entry tool. If you frequently post the same documents with the same data, you can save time and avoid errors by using different reference methods for document entry.SAP makes it easy to create and post a Journal Entry that you can base off of a previously posted document.If you don?t need to set up a full blown Recurring Entry,you can easily copy a previously posted document.SAP gives you several options for what info you?re going to use from the previous document including: ?Generate reverse posting ? will flip the signs on all the lines of the old document ?Enter G/L account items ?Do not propose amounts ? gives you just the accounts?no amounts