Remove Arbitrary Data TLV

doc/MediaSigning.xml

@@ -1124,11 +1124,12 @@
       </section>
       <section xml:id="section_u3s_njq_bwb">
         <title>Arbitrary data</title>
-        <para>This optional field contains Abritrary data that the device vendor want to be
-          included. There is no guarantee that the data is reasonable or readable by
-          anyone not previously knowledgeable in the area.</para>
-        <para xml:id="para_dv5_1gm_4xb">The data tag can be added to any SEI described in
-          this specification or to a SEI of its own.</para>
+        <para>This optional field contains Abritrary data that a device can add to the stream.
+          The data is not used by Media Signing and interpretations is left to the vendor.</para>
+        <para xml:id="para_dv5_1gm_4xb">The data tag shall be added to a separate unsigned SEI,
+          that is, there shall be no other tags present in the SEI when this tag is present.
+          Validation shall be marked as "Not authentic" if this tag is present together with other
+          tags.</para>
         <para>This tag can be useful to add vendor or device specific information and get it
           signed.</para>
       </section>
@@ -1147,6 +1148,12 @@
         correctly verified (partial) GOP hash, all NAL Units now have to be present and
         correct.</para>
     </section>
+    <section xml:id="section_u3s_njq_bwb_2">
+      <title>How a device can add and secure vendor specifc metadata to a stream</title>
+      <para>Generate a Media Signing SEI with only an Arbitrary Data tag; See Section
+        <xref linkend="section_u3s_njq_bwb"/>. This NAL Unit will automatically be hashed
+        and thereby signed.</para>
+    </section>
     <section xml:id="section_w3s_njq_bwb">
       <title>How to generate the first certificate SEI</title>
       <itemizedlist>