diff -r fdf0d272d74a encrypted-media/encrypted-media.html
--- a/encrypted-media/encrypted-media.html	Mon Jan 14 17:46:57 2013 -0800
+++ b/encrypted-media/encrypted-media.html	Mon Jan 14 18:40:18 2013 -0800
@@ -324,7 +324,7 @@
     <ol>
       <li><p>If <var title="true">type</var> is null or an empty string and <var title="true">initData</var> is <em>not</em> null or an empty string, throw an <code><a href="http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#dom-domexception-invalid_access_err">INVALID_ACCESS_ERR</a></code> exception and abort these steps.</p></li>
       
-      <li><p>If <var title="true">type</var> contains a MIME type that is not supported or is not supported by the <code><a href="#dom-keysystem">keySystem</a></code>, throw a <code><a href="http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#dom-domexception-not_supported_err">NOT_SUPPORTED_ERR</a></code> exception and abort these steps.</p></li>
+      <li><p>If <var title="true">type</var> is not supported by the user agent and <code><a href="#dom-keysystem">keySystem</a></code> nor, throw a <code><a href="http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#dom-domexception-not_supported_err">NOT_SUPPORTED_ERR</a></code> exception and abort these steps. <span class="non-normative">In most cases, this means <var title="true">type</var> is not a supported media type.</span></p></li>
 
       <li><p>Let <var title="true">cdm</var> be the <var title="true">cdm</var> loaded in the <a href="#dom-media-keys-constructor"><code>MediaKeys</code> constructor</a>.</p></li>
 
@@ -338,19 +338,20 @@
       <li><p>Add the new object to an internal list of session objects.</p></li>
 
       <li>
-<p>Schedule a task to generate a key request, providing <var title="true">type</var>, <var title="true">initData</var>, and the new object.</p>
+<p>Schedule a task to complete initializion of the session, providing <var title="true">type</var>, <var title="true">initData</var>, and the new object. <span class="non-normative">In most cases, this results in generation of a key request.</span></p>
         <p>The user agent will asynchronously execute the following steps in the task:</p>
         <ol>
           <li><p>Let <var title="true">defaultURL</var> be null.</p></li>
           <li>
-<p>Use <var title="true">cdm</var> to generate a key request and follow the steps for the first matching condition from the following list:</p>
+<p>Use <var title="true">cdm</var> to complete initializion and follow the steps for the first matching condition from the following list:</p>
             <dl class="switch">
-              <dt>If a request is successfully generated</dt>
+              <dt>If the session is succesfully initialized</dt>
               <dd>
               <ol>
                 <li>
-<p>Let <var title="true">key request</var> be a key request generated by the <a href="#cdm">CDM</a> using <var title="true">initData</var>, if provided.</p>
+<p>Let <var title="true">response</var> be a message related to successful initialization.</p>
                   <p>Note: <var title="true">cdm</var> must not use any data, including <a href="http://www.w3.org/TR/html5/video.html#media-data">media data</a>, not provided via <var title="true">initData</var>.</p>
+                  <p class="non-normative">In most cases, this is a key request generated by the <a href="#cdm">CDM</a> using <var title="true">type</var> and <var title="true">initData</var>, if provided.</p>
                   <p class="non-normative"><var title="true">type</var> may be used to determine how to interpret <var title="true">initData</var>.</p>
                 </li>
                 <li><p>If <var title="true">initData</var> is not null and contains a default URL for <var title="true">keySystem</var>, let <var title="true">defaultURL</var> be that URL.</p></li> 
@@ -375,7 +376,7 @@
 <p><a href="http://www.w3.org/TR/html5/webappapis.html#queue-a-task">queue a task</a> to <a href="http://www.w3.org/TR/html5/webappapis.html#fire-a-simple-event">fire a simple event</a> named <code><a href="#dom-keymessage">keymessage</a></code> at the new object</p>
             <p>The event is of type <code><a href="#dom-mediakeymessageevent">MediaKeyMessageEvent</a></code> and has:</p>
             <ul style="list-style-type:none"><li>
-              <code><a href="#dom-message">message</a></code> = <var title="true">key request</var><br>
+              <code><a href="#dom-message">message</a></code> = <var title="true">response</var><br>
               <code><a href="#dom-destinationurl">destinationURL</a></code> = <var title="true">defaultURL</var>
             </li></ul>
             <p class="non-normative">Note: <code><a href="#dom-message">message</a></code> may be a request for multiple keys, depending on the <var title="true"><a href="#key-system">keySystem</a></var> and/or <var title="true">initData</var>. This is transparent to the application.</p>
diff -r fdf0d272d74a encrypted-media/encrypted-media.xml
--- a/encrypted-media/encrypted-media.xml	Mon Jan 14 17:46:57 2013 -0800
+++ b/encrypted-media/encrypted-media.xml	Mon Jan 14 18:40:18 2013 -0800
@@ -317,7 +317,7 @@
     <ol>
       <li><p>If <var title="true">type</var> is null or an empty string and <var title="true">initData</var> is <em>not</em> null or an empty string, throw an <invalid-access-err/> exception and abort these steps.</p></li>
       
-      <li><p>If <var title="true">type</var> contains a MIME type that is not supported or is not supported by the <coderef>keySystem</coderef>, throw a <not-supported-err/> exception and abort these steps.</p></li>
+      <li><p>If <var title="true">type</var> is not supported by the user agent and <coderef>keySystem</coderef> nor, throw a <not-supported-err/> exception and abort these steps. <span class="non-normative">In most cases, this means <var title="true">type</var> is not a supported media type.</span></p></li>
 
       <li><p>Let <var title="true">cdm</var> be the <var title="true">cdm</var> loaded in the <a href="#dom-media-keys-constructor"><code>MediaKeys</code> constructor</a>.</p></li>
 
@@ -330,17 +330,18 @@
       
       <li><p>Add the new object to an internal list of session objects.</p></li>
 
-      <li><p>Schedule a task to generate a key request, providing <var title="true">type</var>, <var title="true">initData</var>, and the new object.</p>
+      <li><p>Schedule a task to complete initializion of the session, providing <var title="true">type</var>, <var title="true">initData</var>, and the new object. <span class="non-normative">In most cases, this results in generation of a key request.</span></p>
         <p>The user agent will asynchronously execute the following steps in the task:</p>
         <ol>
           <li><p>Let <var title="true">defaultURL</var> be null.</p></li>
-          <li><p>Use <var title="true">cdm</var> to generate a key request and follow the steps for the first matching condition from the following list:</p>
+          <li><p>Use <var title="true">cdm</var> to complete initializion and follow the steps for the first matching condition from the following list:</p>
             <dl class="switch">
-              <dt>If a request is successfully generated</dt>
+              <dt>If the session is succesfully initialized</dt>
               <dd>
               <ol>
-                <li><p>Let <var title="true">key request</var> be a key request generated by the <a href="#cdm">CDM</a> using <var title="true">initData</var>, if provided.</p>
+                <li><p>Let <var title="true">response</var> be a message related to successful initialization.</p>
                   <p>Note: <var title="true">cdm</var> must not use any data, including <videoanchor name="media-data">media data</videoanchor>, not provided via <var title="true">initData</var>.</p>
+                  <p class="non-normative">In most cases, this is a key request generated by the <a href="#cdm">CDM</a> using <var title="true">type</var> and <var title="true">initData</var>, if provided.</p>
                   <p class="non-normative"><var title="true">type</var> may be used to determine how to interpret <var title="true">initData</var>.</p>
                 </li>
                 <li><p>If <var title="true">initData</var> is not null and contains a default URL for <var title="true">keySystem</var>, let <var title="true">defaultURL</var> be that URL.</p></li> 
@@ -363,7 +364,7 @@
           <li><p><queue-a-task/> to <fire-a-simple-event/> named <coderef>keymessage</coderef> at the new object</p>
             <p>The event is of type <coderef>MediaKeyMessageEvent</coderef> and has:</p>
             <ul style="list-style-type:none"><li>
-              <coderef>message</coderef> = <var title="true">key request</var><br></br>
+              <coderef>message</coderef> = <var title="true">response</var><br></br>
               <coderef>destinationURL</coderef> = <var title="true">defaultURL</var>
             </li></ul>
             <p class="non-normative">Note: <coderef>message</coderef> may be a request for multiple keys, depending on the <var title="true"><a href="#key-system">keySystem</a></var> and/or <var title="true">initData</var>. This is transparent to the application.</p>