The most widely used and simplest communication method is through data tables. For example, the table No. Series is the central control for all document numbers. Each object that assigns numbers to a document (for example, Order, Invoice, Shipment, and so on) uses Codeunit 396, NoSeriesManagement, to access the No. Series table for the next number to use, and then updates the No. Series table so that the next object needing to assign a number to the same type of document will have the updated information.