diff --git a/include/types/buffers.h b/include/types/buffers.h
index a9de965..7539901 100644
--- a/include/types/buffers.h
+++ b/include/types/buffers.h
@@ -28,12 +28,12 @@
 /* The BF_* macros designate Buffer Flags, which may be ORed in the bit field
  * member 'flags' in struct buffer.
  */
-#define BF_SHUTR_PENDING        1
-#define BF_SHUTR_DONE           2
+#define BF_SHUTR_PENDING        1  /* ignored if BF_SHUTW_DONE */
+#define BF_SHUTR_DONE           2  /* takes precedence over BF_SHUTR_PENDING */
 #define BF_SHUTR_STATUS         (BF_SHUTR_PENDING|BF_SHUTR_DONE)
 
-#define BF_SHUTW_PENDING        4
-#define BF_SHUTW_DONE           8
+#define BF_SHUTW_PENDING        4  /* ignored if BF_SHUTW_DONE */
+#define BF_SHUTW_DONE           8  /* takes precedence over BF_SHUTW_PENDING */
 #define BF_SHUTW_STATUS         (BF_SHUTW_PENDING|BF_SHUTW_DONE)
 
 #define BF_PARTIAL_READ        16