EDIFACT is an international EDI standard used by companies worldwide. Due to the international nature of the standard, each message within the standard is very comprehensive. This has lead to a number of industry specific standards based upon EDIFACT being created. The industry specific standards tend to be subsets of the EDIFACT message. This reduces the complexity of the messages and hence eases implementation. A popular subset of EDIFACT is EANCOM, which is designed for international trade and based on the EDIFACT D96A directory. National standards bodies also create their own subset for their particular, and in some cases, unique national requirements. The UK has its own national standard Tradacoms which is meant for domestic trade, Tradacoms is distinct from EDIFACT and has a large number of differences. There is also a UK standard based on UN EDIFACT, known as UK EDIFACT which is derived from UN EDIFACT D96A.

EDIFACT and other industry specific standards have created a series of messages that can be used for specific tasks. These messages have 6 character names, for example ORDERS (Order Message), INVOIC (Invoice Message), DEBADV (Debit Advice) etc.

As time has gone by new messages have been added to the standard and the original messages have been updated. There are now over a dozen versions of a standard orders message. A full list of the defined messages and the versions can be found at http://www.unece.org/trade/untdid/welcome.htm