Add some documentation
diff --git a/include/grpc/grpc.h b/include/grpc/grpc.h
index 561bc9a..f6c7da4 100644
--- a/include/grpc/grpc.h
+++ b/include/grpc/grpc.h
@@ -550,15 +550,24 @@
 grpc_call_error grpc_server_request_call_old(grpc_server *server,
                                              void *tag_new);
 
+/* Request notification of a new call */
 grpc_call_error grpc_server_request_call(
     grpc_server *server, grpc_call **call, grpc_call_details *details,
     grpc_metadata_array *request_metadata,
     grpc_completion_queue *cq_bound_to_call, 
     void *tag_new);
 
+/* Registers a method in the server.
+   Methods to this (host, method) pair will not be reported by
+   grpc_server_request_call, but instead be reported by 
+   grpc_server_request_registered_call when passed the appropriate
+   registered_method (as returned by this function).
+   Must be called before grpc_server_start.
+   Returns NULL on failure. */
 void *grpc_server_register_method(grpc_server *server, const char *method,
                                   const char *host);
 
+/* Request notification of a new pre-registered call */
 grpc_call_error grpc_server_request_registered_call(
     grpc_server *server, void *registered_method, grpc_call **call,
     gpr_timespec *deadline, grpc_metadata_array *request_metadata,