diff --git a/doc/Security.xml b/doc/Security.xml
index 584313f93..786a810fd 100644
--- a/doc/Security.xml
+++ b/doc/Security.xml
@@ -4408,7 +4408,7 @@
           certificate in the chain and its associated private key shall be used for signing media as
           described in the [Media Signing Specification]. This key and certificate are referred to
           as user provisioned key and certificate in that specification.</para>
-        <para>If a user-provisioned certification path is configured, it shall be replaced by the
+        <para>If a user provisioned certification path is configured, it shall be replaced by the
           new certification path only if it is not in use by an ongoing media streaming session;
           otherwise, the device shall return a ReferenceExists fault and shall not replace the
           certification path.</para>
@@ -4498,8 +4498,8 @@
           AddMediaSigningCertificateAssignment.</para>
         <para>A device shall support this command if the MediaSigningSupported capability is
           true.</para>
-        <para>Response list shall be ordered with factory-provisioned ID first, followed by
-          user-provisioned ID.</para>
+        <para>Response list shall be ordered with factory-provisioned ID first, followed by user
+          provisioned ID.</para>
         <variablelist role="op">
           <varlistentry>
             <term>request</term>
@@ -5590,7 +5590,46 @@
 </tt:MessageDescription>
 ]]></programlisting>
       </section>
+      <section xml:id="section_lhd_zp3_hjc">
+          <title>Media signing key assignment status</title>
+          <para>A device that indicates support for signing of media using a user provisioned key
+            via the UserMediaSigningKeySupported capability shall provide information about assigned
+            key changes via the below specified event</para>
+          <programlisting><![CDATA[Topic: tns1:Advancedsecurity/MediaSigning/KeyStatus
+<tt:MessageDescription IsProperty="true">
+  <tt:Source>
+    <tt:SimpleItemDescription Name="KeyID" Type="tas:KeyID"/>
+  </tt:Source>
+  <tt:Data>
+    <tt:SimpleItemDescription Name="Effective" Type="xs:boolean"/>
+  </tt:Data>
+</tt:MessageDescription>
+]]></programlisting>
+          <para>When user provisioned key is configured via <emphasis role="bold"
+              >AddMediaSigningCertificateAssignment</emphasis> and If there are no active signed
+            streams using manufacturer key, Changed property event with the KeyID set to user
+            provisioned key shall be triggered with 'Effective' status set to True, indicating that
+            new signed streams shall use the user provisioned key for signing immediately.</para>
+          <para>When user provisioned key is configured via <emphasis role="bold"
+              >AddMediaSigningCertificateAssignment</emphasis> and If there are active signed
+            streams using manufacturer key, Changed property event with the KeyID set to user
+            provisioned key shall be triggered with 'Effective' status set to False, indicating that
+            ongoing signed streams shall continue using the manufacturer key until
+            terminated.</para>
+          <para>When configured user provisioned key is removed via <emphasis role="bold"
+              >RemoveMediaSigningCertificateAssignment</emphasis> and If there are no active signed
+            streams using user provisioned key, Changed property event with the KeyID set to
+            manufacturer key shall be triggered with 'Effective' status set to True, indicating that
+            new signed streams shall use the manufacturer key for signing immediately.</para>
+          <para>When configured user provisioned key is removed via <emphasis role="bold"
+              >RemoveMediaSigningCertificateAssignment</emphasis> and If there are no active signed
+            streams using user provisioned key, Changed property event with the KeyID set to
+            manufacturer key shall be triggered with 'Effective' status set to False, indicating
+            that ongoing signed streams shall continue using the user provisioned key until
+            terminated.</para>
+        </section>
     </section>
+    
     <section>
       <title>Service specific data types</title>
       <para>The service specific data types are defined in security.wsdl.</para>