diff --git a/experimental/xx-input-method/xx-input-method-v2.xml b/experimental/xx-input-method/xx-input-method-v2.xml
index 9015e61..38e193f 100644
--- a/experimental/xx-input-method/xx-input-method-v2.xml
+++ b/experimental/xx-input-method/xx-input-method-v2.xml
@@ -467,7 +467,11 @@
         <!-- Alternative: compositor assumes the events are confirmed automatically. Downside: harder to specify the model of ordering events when some serials are missing. -->
 
         Sequence:
-        The serial must always correspond to the last event after the last committed .activate which hasn't yet received a .keyboard_consume confirmation. Events must be confirmed in order. That is, if the compositor receives a serial corresponding to an event after such last event, it must issue the invalid_serial protocol error. The invalid_serial protocol error must also be issued if the serial corresponds to an already confirmed event, or no previous event, or an event arrived before the last committed .activate.
+        The keyboard begins to receive events after input_method.activate is committed.
+        The valid serial is the serial of the oldest wl_keyboard event which has been sent after input_method.activate but which hasn't yet received a .filter confirmation.
+        The compositor may raise the invalid_serial error in response toevents with serials it had not issued.
+        The compositor must ignore events with all other serials. (Particularly, this means events with repeating serials are accepted normally and are not ignored).
+        Events must be filtered in order.
       </description>
       <arg name="serial" type="uint"/>
       <arg name="action" type="uint" enum="filter_action"/>