A number range must be assigned to each document type. For more information, see Document Number Assignment in the R/3 System.

During document entry, a number within the number range assigned to that document type must be selected for the document. If you always store original documents under their processing document number, you can control how these documents are filed by using document types. All original documents that are posted with the same document type in the system are filed together. However, you also have the option to store several document types together.

You use document types to differentiate postings according to accounting transaction. If you want to file documents separately by document type, you need to assign a separate number range to each document type. In the following illustration, document type KG (vendor credit memo) was assigned to number range 01, and document type KR (vendor invoice) was assigned to number range 02. The original documents are stored accordingly.

If you want to file several document types together, you need to assign the same number range to them. For instance, you can differentiate the posting of vendor credit memos (document type KG) and vendor invoices (document type KR) using document types and can file these documents together by assigning the same number range to each document type.