Within an ABAP backend, a lot of system documentation can be found for the topics "ABAP Proxy Generation" / "ABAP Web Service Creation". You can access this documentation the following way:
- Start Transaction SPROXY
- Check the buttons in the toolbar above the "Enterprise Services Repository" Tree. Now depending on your SAP Basis Release:
- If a blue "i"-Button can be found, click on it.
- If no blue "i"-Button can be found, simply display a generated Web Service Proxy (Provider, Consumer, Message- or Datatype does not matter), and look for the blue "i"-Button within the application toolbar. Click the button.
The popup being displayed after the button has been clicked provides further links to a lot of different aspects regarding ABAP proxy generation.