diff --git a/pageant.c b/pageant.c
index e0f77c30..1c34d71c 100644
--- a/pageant.c
+++ b/pageant.c
@@ -36,7 +36,7 @@
 /* From MSDN: In the WM_SYSCOMMAND message, the four low-order bits of
  * wParam are used by Windows, and should be masked off, so we shouldn't
  * attempt to store information in them. Hence all these identifiers have
- * the low 4 bits clear. */
+ * the low 4 bits clear. Also, identifiers should < 0xF000. */
 
 #define IDM_CLOSE    0x0010
 #define IDM_VIEWKEYS 0x0020