Put responses and notifications in notification packets

Author: emhane

discv5/discv5-wire.md

@@ -110,6 +110,8 @@ of `authdata`, which differs depending on the packet type.
 ### Ordinary Message Packet (`flag = 0`)
 
 For message packets, the `authdata` section is just the source node ID.
+[Protocol messages](#protocol-messages) of type request are transported in the
+`message` field of this packet.
 
     authdata      = src-id
     authdata-size = 32
@@ -159,16 +161,19 @@ handshake packet.
 Aside from the flag value, this container is identical to a
 [message packet](#ordinary-message-packet). Contrary to a message packet, failing to
 decrypt a notification packet should not trigger a handshake.
+[Protocol messages](#protocol-messages) of type response and notification are transported
+in the `message` field of this packet.
 
 ## Protocol Messages
 
 This section lists all defined messages which can be sent and received. The hexadecimal
 value in parentheses is the `message-type`.
 
-The first element of every `message-data` list is the request ID. `request-id` is an RLP
-byte array of length <= 8 bytes. For requests, this value is assigned by the requester.
-The recipient of a message must mirror the value in the `request-id` element of the
-response. The selection of appropriate values for request IDs is left to the implementation.
+For request and response messages, the first element of every `message-data` list is the
+request ID. `request-id` is an RLP byte array of length <= 8 bytes. For requests, this value
+is assigned by the requester. The recipient of a message must mirror the value in the
+`request-id` element of the response. The selection of appropriate values for request IDs is
+left to the implementation.
 
 ### PING Request (0x01)
 
@@ -297,20 +302,15 @@ TOPICQUERY requests nodes in the [topic queue] of the given topic. The recipient
 request must send one or more NODES messages containing node records registered for the
 topic.
 
-## Protocol Notifications
-
-This section lists all defined notifications which can be sent and received. The hexadecimal
-value in parentheses is the `notification-type`.
-
-### RELAYINIT (0x01)
+### RELAYINIT Notification (0x0B)
 
     message-data      = [inr-enr, tgt-id, nonce]
     notification-type = 0x01
     inr-enr           = initiator ENR
     tgt-id            = 256-bit node ID of target
     nonce             = uint96    -- nonce of timed out request
 
-### RELAYMSG (0x02)
+### RELAYMSG Notification (0x0C)
 
     message-data      = [inr-enr, nonce]
     notification-type = 0x02