XML-RPC specification doesn’t provide default methods to achieve introspection tasks, but some people proposed a standard for such methods. The original document is now offline, but has been retrieved from Google cache and is now hosted here.
Return a list of all methods available.
Return the signature of a specific method
Return the documentation for a specific method.
Like 3 others, this system method is not part of the standard. But its behavior has been well defined by Eric Kidd. It is now implemented most of the XML-RPC servers and supported by number of clients (including Python’s ServerProxy).
This method can be used to make many RPC calls at once, by sending an array of RPC payload. The result is a list of responses, with the result for each individual request, or a corresponding fault result.
It is available only to XML-RPC clients, since JSON-RPC protocol specify how to call multiple RPC methods at once using batch request.