Starting in 4D 2004, DOC style Web Services is now supported as well as RPC style for both Web Services Client and Server.
Here are simple steps to publish a method in a DOC and RPC style Web Service:
1- Open the Method Properties of the method that you want to publish and check the checkbox for "Offer as a Web Service" and "Published in WSDL"
2. Open the Database Preferences and enable the option "Allow Web Services Requests" in the web Services settings.
To discover Web Services from 4D, go to the Design mode and choose Web Services Wizard... from the Design menu.
For RPC style Web Services from 4D, the URL that you need to discover would be in the following format: https://HostNameOrIP/4dwsdl.
For DOC style Web Services from, the URL that you need to discover would be in the following format: https://HostNameOrIP/4dwsdl/doc.