diff --git a/core/net/rime/packetbuf.h b/core/net/rime/packetbuf.h
index a57bcef96..b153f1a60 100644
--- a/core/net/rime/packetbuf.h
+++ b/core/net/rime/packetbuf.h
@@ -40,7 +40,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: packetbuf.h,v 1.5 2010/02/06 07:48:52 adamdunkels Exp $
+ * $Id: packetbuf.h,v 1.6 2010/02/28 09:19:43 adamdunkels Exp $
  */
 
 /**
@@ -325,37 +325,40 @@ struct packetbuf_addr {
   rimeaddr_t addr;
 };
 
-extern const char *packetbuf_attr_strings[];
-
 #define PACKETBUF_ATTR_PACKET_TYPE_DATA 0
 #define PACKETBUF_ATTR_PACKET_TYPE_ACK 1
 #define PACKETBUF_ATTR_PACKET_TYPE_STREAM 2
 
 enum {
   PACKETBUF_ATTR_NONE,
+
+  /* Scope 0 attributes: used only on the local node. */
   PACKETBUF_ATTR_CHANNEL,
-  PACKETBUF_ATTR_PACKET_ID,
-  PACKETBUF_ATTR_PACKET_TYPE,
-  PACKETBUF_ATTR_EPACKET_ID,
-  PACKETBUF_ATTR_EPACKET_TYPE,
-  PACKETBUF_ATTR_HOPS,
-  PACKETBUF_ATTR_TTL,
-  PACKETBUF_ATTR_REXMIT,
-  PACKETBUF_ATTR_MAX_REXMIT,
-  PACKETBUF_ATTR_NUM_REXMIT,
+  PACKETBUF_ATTR_NETWORK_ID,
   PACKETBUF_ATTR_LINK_QUALITY,
   PACKETBUF_ATTR_RSSI,
   PACKETBUF_ATTR_TIMESTAMP,
   PACKETBUF_ATTR_RADIO_TXPOWER,
-
   PACKETBUF_ATTR_LISTEN_TIME,
   PACKETBUF_ATTR_TRANSMIT_TIME,
-  
-  PACKETBUF_ATTR_NETWORK_ID,
-  
+  PACKETBUF_ATTR_MAX_MAC_REXMIT,
+
+  /* Scope 1 attributes: used between two neighbors only. */
   PACKETBUF_ATTR_RELIABLE,
+  PACKETBUF_ATTR_PACKET_ID,
+  PACKETBUF_ATTR_PACKET_TYPE,
+  PACKETBUF_ATTR_REXMIT,
+  PACKETBUF_ATTR_MAX_REXMIT,
+  PACKETBUF_ATTR_NUM_REXMIT,
+  
+  /* Scope 2 attributes: used between end-to-end nodes. */
+  PACKETBUF_ATTR_HOPS,
+  PACKETBUF_ATTR_TTL,
+  PACKETBUF_ATTR_EPACKET_ID,
+  PACKETBUF_ATTR_EPACKET_TYPE,
   PACKETBUF_ATTR_ERELIABLE,
 
+  /* These must be last */
   PACKETBUF_ADDR_SENDER,
   PACKETBUF_ADDR_RECEIVER,
   PACKETBUF_ADDR_ESENDER,