diff --git a/docs/udp_tracker_protocol.html b/docs/udp_tracker_protocol.html
index 35671381f..378cc5ee7 100644
--- a/docs/udp_tracker_protocol.html
+++ b/docs/udp_tracker_protocol.html
@@ -34,8 +34,10 @@
 </ul>
 </li>
 <li><a class="reference" href="#actions" id="id18" name="id18">actions</a></li>
-<li><a class="reference" href="#extensions" id="id19" name="id19">extensions</a></li>
+<li><a class="reference" href="#extensions" id="id19" name="id19">extensions</a><ul>
 <li><a class="reference" href="#authentication" id="id20" name="id20">authentication</a></li>
+</ul>
+</li>
 <li><a class="reference" href="#credits" id="id21" name="id21">credits</a></li>
 </ul>
 </div>
@@ -73,7 +75,9 @@ retrying.</p>
 <tbody valign="top">
 <tr><td>int64_t</td>
 <td>connection_id</td>
-<td>Not used, ignored by tracker.</td>
+<td>Must be initialized to 0x41727101980
+in network byte order. This will
+identify the protocol.</td>
 </tr>
 <tr><td>int32_t</td>
 <td>action</td>
@@ -150,7 +154,8 @@ establishing the connection.</td>
 </tr>
 <tr><td>int32_t</td>
 <td>action</td>
-<td>Action. in this case, 1 for announce.</td>
+<td>Action. in this case, 1 for announce.
+See <a class="reference" href="#actions">actions</a>.</td>
 </tr>
 <tr><td>int32_t</td>
 <td>transaction_id</td>
@@ -239,7 +244,8 @@ in the reply. Use -1 for default.</td>
 <td>action</td>
 <td>The action this is a reply to. Should
 in this case be 1 for announce.
-If 3 (for error) see <a class="reference" href="#errors">errors</a>.</td>
+If 3 (for error) see <a class="reference" href="#errors">errors</a>.
+See <a class="reference" href="#actions">actions</a>.</td>
 </tr>
 <tr><td>int32_t</td>
 <td>transaction_id</td>
@@ -315,7 +321,7 @@ establishing of the connection.</td>
 <tr><td>int32_t</td>
 <td>action</td>
 <td>The action, in this case, 2 for
-scrape.</td>
+scrape. See <a class="reference" href="#actions">actions</a>.</td>
 </tr>
 <tr><td>int32_t</td>
 <td>transaction_id</td>
@@ -380,7 +386,8 @@ If 3 (for error) see <a class="reference" href="#errors">errors</a>.</td>
 </tr>
 </tbody>
 </table>
-<p>The rest of the packet contains a variable number of the following structures:</p>
+<p>The rest of the packet contains the following structures once for each info-hash
+you asked in the scrape request.</p>
 <table border class="table">
 <colgroup>
 <col width="18%" />
@@ -432,7 +439,8 @@ leechers.</td>
 <tbody valign="top">
 <tr><td>int32_t</td>
 <td>action</td>
-<td>The action, in this case 3, for error.</td>
+<td>The action, in this case 3, for error.
+See <a class="reference" href="#actions">actions</a>.</td>
 </tr>
 <tr><td>int32_t</td>
 <td>transaction_id</td>
@@ -469,9 +477,8 @@ bits are assigned:</p>
 <li>1 = <a class="reference" href="#authentication">authentication</a>.</li>
 </ul>
 </blockquote>
-</div>
 <div class="section" id="authentication">
-<h1><a name="authentication">authentication</a></h1>
+<h2><a name="authentication">authentication</a></h2>
 <p>The packet will have an authentication part
 appended to it. It has the following format:</p>
 <table border class="table">
@@ -497,16 +504,19 @@ username.</td>
 <td>The username, the number of characters
 as specified in the previous field.</td>
 </tr>
-<tr><td>uint8_t[20]</td>
+<tr><td>uint8_t[8]</td>
 <td>passwd_hash</td>
 <td>sha1(packet + sha1(password))
 The packet in this case means the
-entire packet except these 20 bytes
-that are the password hash.</td>
+entire packet except these 8 bytes
+that are the password hash. These are
+the 8 first bytes (most significant)
+from the 20 bytes hash calculated.</td>
 </tr>
 </tbody>
 </table>
 </div>
+</div>
 <div class="section" id="credits">
 <h1><a name="credits">credits</a></h1>
 <p>Protocol designed by Olaf van der Spek</p>
diff --git a/docs/udp_tracker_protocol.rst b/docs/udp_tracker_protocol.rst
index e541b69ca..8eefb29eb 100755
--- a/docs/udp_tracker_protocol.rst
+++ b/docs/udp_tracker_protocol.rst
@@ -40,7 +40,9 @@ Client sends packet:
 +-------------+---------------------+----------------------------------------+
 | size        | name                | description                            |
 +=============+=====================+========================================+
-| int64_t     | connection_id       | Not used, ignored by tracker.          |
+| int64_t     | connection_id       | Must be initialized to 0x41727101980   |
+|             |                     | in network byte order. This will       |
+|             |                     | identify the protocol.                 |
 +-------------+---------------------+----------------------------------------+
 | int32_t     | action              | 0 for a connection request             |
 +-------------+---------------------+----------------------------------------+
@@ -83,6 +85,7 @@ Client sends packet:
 |             |                     | establishing the connection.           |
 +-------------+---------------------+----------------------------------------+
 | int32_t     | action              | Action. in this case, 1 for announce.  |
+|             |                     | See actions_.                          |
 +-------------+---------------------+----------------------------------------+
 | int32_t     | transaction_id      | Randomized by client.                  |
 +-------------+---------------------+----------------------------------------+
@@ -132,6 +135,7 @@ Server replies with packet:
 | int32_t     | action              | The action this is a reply to. Should  |
 |             |                     | in this case be 1 for announce.        |
 |             |                     | If 3 (for error) see errors_.          |
+|             |                     | See actions_.                          |
 +-------------+---------------------+----------------------------------------+
 | int32_t     | transaction_id      | Must match the transaction_id sent     |
 |             |                     | in the announce request.               |
@@ -172,7 +176,7 @@ Client sends packet:
 |             |                     | establishing of the connection.        |
 +-------------+---------------------+----------------------------------------+
 | int32_t     | action              | The action, in this case, 2 for        |
-|             |                     | scrape.                                |
+|             |                     | scrape. See actions_.                  |
 +-------------+---------------------+----------------------------------------+
 | int32_t     | transaction_id      | Randomized by client.                  |
 +-------------+---------------------+----------------------------------------+
@@ -204,7 +208,8 @@ Server replies with packet:
 | int32_t     | transaction_id      | Must match the sent transaction id.    |
 +-------------+---------------------+----------------------------------------+
 
-The rest of the packet contains a variable number of the following structures:
+The rest of the packet contains the following structures once for each info-hash
+you asked in the scrape request.
 
 +-------------+---------------------+----------------------------------------+
 | size        | name                | description                            |
@@ -231,6 +236,7 @@ server replies packet:
 | size        | name                | description                            |
 +=============+=====================+========================================+
 | int32_t     | action              | The action, in this case 3, for error. |
+|             |                     | See actions_.                          |
 +-------------+---------------------+----------------------------------------+
 | int32_t     | transaction_id      | Must match the transaction_id sent     |
 |             |                     | from the client.                       |
@@ -262,7 +268,7 @@ bits are assigned:
 
 
 authentication
-++++++++++++++
+--------------
 
 The packet will have an authentication part
 appended to it. It has the following format:
@@ -276,10 +282,12 @@ appended to it. It has the following format:
 | int8_t[]    | username            | The username, the number of characters |
 |             |                     | as specified in the previous field.    |
 +-------------+---------------------+----------------------------------------+
-| uint8_t[20] | passwd_hash         | sha1(packet + sha1(password))          |
+| uint8_t[8]  | passwd_hash         | sha1(packet + sha1(password))          |
 |             |                     | The packet in this case means the      |
-|             |                     | entire packet except these 20 bytes    |
-|             |                     | that are the password hash.            |
+|             |                     | entire packet except these 8 bytes     |
+|             |                     | that are the password hash. These are  |
+|             |                     | the 8 first bytes (most significant)   |
+|             |                     | from the 20 bytes hash calculated.     |
 +-------------+---------------------+----------------------------------------+