Description
e-ordering refers a number of business processes related to ordering good or services in a supply chain. To understand the concept of a business process, see Supply-chain business processes. A number of data standards are used to encode business documents being exchanged during these business processes (see Supply-chain data standards).
In the UBL standard, document types in these processes are Order, Order Response, Order Response Simple, Order Change, and Order Cancellation. The diagram below shows the business process that connects them:

Resources
Definitions and principles
The UBL 2.4 standard has a section dedicated to ordering (section 2.3.3 Procurement).
e-Ordering Document Standards
The older EDIFACT standard defines the ORDERS, DELFOR and DELJIT messages as a standard, all information is available e.g. UN/EDIFACT D.11A – Message [ORDERS]
FAQ
What are the main GS1 XML documents for ordering
They are Order | GS1 and Order Response | GS1
