What are IDocs?

IDocs are structured ASCII files (or a virtual equivalent). They are the file format used by SAP
R/3 to exchange data with foreign systems.

IDocs are simple ASCII data streams. When they are stored to a disk file, the IDocs
are simple flat files with lines of text, where the lines are structured into data fields.
The typical structured file has records, each record starting with a leading string that
identifies the record type. Their specification is stored in the data dictionary.
IDocs is the acronym for Interchange Document. This indicates a set of (electronic)
information which builds a logical entity. An IDoc is e.g. all the data of a single
customer in your customer master data file, or the IDoc is all the data of a single
invoice.

IDoc data is usually exchanged between systems and partners that are completely
independent. Therefore, the data should be transmitted in a format that can easily be
corrected by the computer operators. It is therefore mandatory to post the data in a
human readable form.

Nowadays, this means that data is coded in ASCII format, including numbers which
are sent as a string of figures 0 to 9. Such data can easily be read with any text editor
on any computer, be it a PC, Macintosh, UNIX System, S/390 or any internet
browser.

The information which is exchanged by IDocs is called a message and the IDoc is
the physical representation of such a message. The name “messages” for the
information sent via IDocs is used in the same ways as other EDI standards. .
Everybody who has ever dealt with interface programming, will find IDocs very
much like the hierarchical data files used in traditional data exchange.
International standards like the ODETTE or VDA formats are designed in the same
way as IDocs are.

Other EDI standards like XML, ANSI X.12 or EDIFACT/UN are based on a data
description language. They differ principally from the IDocs concept, because they
use a programming language syntax (e.g. like Postscript or HTML) to embed the
data.