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         contributions to this work.
       </p>
     </section>
+    <section id="substantive-changes-summary" class="appendix informative">
+      <h2>Summary of substantive changes</h2>
+      <section id="substantive-changes-summary-fpwd">
+        <h3>Changes since the <a href="https://www.w3.org/TR/2020/WD-screen-fold-20201217/">First Public Working Draft (2020/12/17)</a></h3>
+        <ul>
+          <li><a href="https://github.com/w3c/device-posture/pull/155">Remove the rate limiting section per PING review</a> (PR #155)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/149">Add two new comments from the accessibility review</a> (PR #149)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/145">Update Privacy considerations</a> (PR #145)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/141">Add automation support via WebDriver</a> (PR #141)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/138">Remove the focus part of the spec</a> (PR #138)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/132">Improve the privacy section</a> (PR #132)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/127">Add accessibility section</a> (PR #127)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/128">device posture change steps: Refer to disallowRecursion by name in calls</a> (PR #128)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/120">Modernize algorithms in "Algorithm" section</a> (PR #120)</li>
+          <!-- PR #112 was removed by PR #114 -->
+          <li><a href="https://github.com/w3c/device-posture/pull/100">Remove Folded Over from Device Posture</a> (PR #100)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/87">Updated folding related concepts</a> (PR #87)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/75">Use internal slot</a> (PR #75)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/73">Add info about using additional signals</a> (PR #73)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/71">Move the entry point of the API to the window.navigator interface</a> (PR #71)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/58">Remove fold angle value from the specification</a> (PR #58)</li>
+          <li><a href="https://github.com/w3c/device-posture/pull/42">Improve the Privacy and Security section</a> (PR #42)</li>
+        </ul>
+    </section>
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