Index: kernel/generic/include/ddi/irq.h
===================================================================
--- kernel/generic/include/ddi/irq.h	(revision dd8d5a73bdea8475dd6109269d442c9d31c454a6)
+++ kernel/generic/include/ddi/irq.h	(revision 7bdcc45cafcbc371db7a254d626b5ddfbb07e20f)
@@ -122,6 +122,6 @@
 	/** Answerbox for notifications. */
 	answerbox_t *answerbox;
-	/** Method to be used for the notification. */
-	sysarg_t method;
+	/** Interface and method to be used for the notification. */
+	sysarg_t imethod;
 	/** Arguments that will be sent if the IRQ is claimed. */
 	uint32_t scratch[IPC_CALL_LEN];
Index: kernel/generic/include/ipc/event.h
===================================================================
--- kernel/generic/include/ipc/event.h	(revision dd8d5a73bdea8475dd6109269d442c9d31c454a6)
+++ kernel/generic/include/ipc/event.h	(revision 7bdcc45cafcbc371db7a254d626b5ddfbb07e20f)
@@ -47,6 +47,6 @@
 	/** Answerbox for notifications. */
 	answerbox_t *answerbox;
-	/** Method to be used for the notification. */
-	sysarg_t method;
+	/** Interface and method to be used for the notification. */
+	sysarg_t imethod;
 	/** Counter. */
 	size_t counter;
Index: kernel/generic/include/ipc/ipc.h
===================================================================
--- kernel/generic/include/ipc/ipc.h	(revision dd8d5a73bdea8475dd6109269d442c9d31c454a6)
+++ kernel/generic/include/ipc/ipc.h	(revision 7bdcc45cafcbc371db7a254d626b5ddfbb07e20f)
@@ -84,5 +84,5 @@
 /* Macros for manipulating calling data */
 #define IPC_SET_RETVAL(data, retval)  ((data).args[0] = (retval))
-#define IPC_SET_METHOD(data, val)     ((data).args[0] = (val))
+#define IPC_SET_IMETHOD(data, val)    ((data).args[0] = (val))
 #define IPC_SET_ARG1(data, val)       ((data).args[1] = (val))
 #define IPC_SET_ARG2(data, val)       ((data).args[2] = (val))
@@ -91,6 +91,6 @@
 #define IPC_SET_ARG5(data, val)       ((data).args[5] = (val))
 
-#define IPC_GET_METHOD(data)  ((data).args[0])
-#define IPC_GET_RETVAL(data)  ((data).args[0])
+#define IPC_GET_IMETHOD(data)  ((data).args[0])
+#define IPC_GET_RETVAL(data)   ((data).args[0])
 
 #define IPC_GET_ARG1(data)  ((data).args[1])
@@ -116,6 +116,13 @@
 #define IPC_FF_ROUTE_FROM_ME  (1 << 0)
 
+/** Kernel IPC interfaces
+ *
+ */
+#define IPC_IF_KERNEL  0
+
 /** System-specific methods - only through special syscalls
- * These methods have special behaviour
+ *
+ * These methods have special behaviour. These methods also
+ * have the implicit kernel interface 0.
  *
  */