diff --git a/Protocol.md b/Protocol.md
index f4e69c1..96918d0 100644
--- a/Protocol.md
+++ b/Protocol.md
@@ -29,10 +29,6 @@ Extends `int`, contains a second based UNIX timestamp.
 A `string` containing only alphanumeric characters (any case), `-` or `_`.
 
 
-### `session id`
-A `string` containing only alphanumeric characters (any case), `-` or `_`.
-
-
 ### `color`
 Any valid value for the CSS `color` property.
 Further documentation can be found [on MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/color_value).
@@ -93,7 +89,7 @@ Used to prevent the client from closing the session due to inactivity.
 
 <table>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>User ID</td>
         <td></td>
     </tr>
@@ -119,7 +115,7 @@ Commands are described lower in the document.
 
 <table>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>User ID</td>
         <td></td>
     </tr>
@@ -159,7 +155,7 @@ Informs the client that authentication has succeeded.
         <td></td>
     </tr>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>User ID</td>
         <td></td>
     </tr>
@@ -231,7 +227,7 @@ Informs the client that a user has joined.
         <td></td>
     </tr>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>User ID</td>
         <td></td>
     </tr>
@@ -251,7 +247,7 @@ Informs the client that a user has joined.
         <td></td>
     </tr>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>Sequence ID</td>
         <td></td>
     </tr>
@@ -268,7 +264,7 @@ Informs the client that a chat message has been received.
         <td></td>
     </tr>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>
             User ID.
             If <code>-1</code> this message is an informational message from the server and the next field takes on a special form.
@@ -306,7 +302,7 @@ Informs the client that a chat message has been received.
         <td></td>
     </tr>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>Sequence ID</td>
         <td></td>
     </tr>
@@ -323,7 +319,7 @@ Informs the client that a user has disconnected.
 
 <table>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>User ID</td>
         <td></td>
     </tr>
@@ -351,7 +347,7 @@ Informs the client that a user has disconnected.
         <td></td>
     </tr>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>Sequence ID</td>
         <td></td>
     </tr>
@@ -462,7 +458,7 @@ Informs the client that a user has joined the channel.
 
 <table>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>User ID</td>
         <td></td>
     </tr>
@@ -482,7 +478,7 @@ Informs the client that a user has joined the channel.
         <td></td>
     </tr>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>Sequence ID</td>
         <td></td>
     </tr>
@@ -494,12 +490,12 @@ Informs the client that a user has left the channel.
 
 <table>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>User ID</td>
         <td></td>
     </tr>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>Sequence ID</td>
         <td></td>
     </tr>
@@ -523,7 +519,7 @@ Informs the client that a message has been deleted.
 
 <table>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>Sequence ID of the deleted message</td>
         <td></td>
     </tr>
@@ -568,7 +564,7 @@ Informs the client about users already present in the channel.
 
 <table>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>User ID</td>
         <td></td>
     </tr>
@@ -605,7 +601,7 @@ Informs the client about an existing message in a channel.
         <td></td>
     </tr>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>User ID</td>
         <td></td>
     </tr>
@@ -630,7 +626,7 @@ Informs the client about an existing message in a channel.
         <td></td>
     </tr>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>Sequence ID</td>
         <td></td>
     </tr>
@@ -732,7 +728,7 @@ Informs that another user's details have been updated.
 
 <table>
     <tr>
-        <td><code>int</code></td>
+        <td><code>string</code></td>
         <td>User ID of the affected user</td>
         <td></td>
     </tr>
diff --git a/SharpChat/ChatChannel.cs b/SharpChat/ChatChannel.cs
index c239497..2c6bb5e 100644
--- a/SharpChat/ChatChannel.cs
+++ b/SharpChat/ChatChannel.cs
@@ -85,7 +85,7 @@ namespace SharpChat {
         }
 
         public static bool CheckNameChar(char c) {
-            return char.IsLetter(c) || char.IsNumber(c) || c == '-';
+            return char.IsLetter(c) || char.IsNumber(c) || c == '-' || c == '_';
         }
     }
 }