I've been digging in the LiveCycle docs and finally I've found documentation regarding the specification of the service-config.xml file here:
But I couldn't find the DTD or XML Schema for this specification. Is it available somewhere? If not, why won't Adobe provide a public DTD/XML Schema so that developers can easily validate their configuration files?
You are correct that there is no XML Schema for our configuration files.
One of the reasons is that custom adapters can configure any settings they need in their destinations. The other reason is that the server will not start if there is anything in the config XML that isn't read by the server on startup. This ensures that mis-spellings and invalid tags do not get ignored.
You are right however, we should create an xsd for them. I filed an enhancement request - #2726353.