diff --git a/source b/source
index 97abc1f8269..1b155fff3a2 100644
--- a/source
+++ b/source
@@ -79602,6 +79602,14 @@ interface <dfn>BarProp</dfn> {
    <var>window</var>'s <span data-x="concept-document-window">associated
    <code>Document</code></span>.</p></li>
 
+   <li><p>Let <var>canBeCrossOriginIsolated</var> be true if the user agent is willing to give access
+   to <code data-x="cross-origin-isolated-feature">cross-origin-isolated</code> features, and false
+   otherwise.</p>
+   <p class="note">Not every platform can easily support the security properties associated with the
+   <code data-x="cross-origin-isolated-feature">cross-origin-isolated</code> feature. Once the
+   decision to support it has been made, it is guaranteed not to change over time.</p>
+   </li>
+
    <li>
     <p>Let <var>settings object</var> be a new <span>environment settings object</span> whose
     algorithms are defined as follows:</p>
@@ -79668,11 +79676,19 @@ interface <dfn>BarProp</dfn> {
 
      <dt>The <span data-x="concept-settings-object-cross-origin-isolated-capability">cross-origin
      isolated capability</span></dt>
-     <dd><p>Return the logical conjunction of <var>realm</var>'s <span>agent cluster</span>'s
-     <span>cross-origin isolated</span> and whether <var>window</var>'s <span
-     data-x="concept-document-window">associated <code>Document</code></span> is <span>allowed to
-     use</span> the "<code data-x="cross-origin-isolated-feature">cross-origin-isolated</code>"
-     feature.</p></dd>
+     <dd><p>Return the logical conjunction of:</p>
+     <ol>
+       <li><p><var>canBeCrossOriginIsolated</var></p></li>
+
+       <li><p><var>realm</var>'s <span>agent cluster</span>'s <span>cross-origin
+       isolated</span></p></li>
+
+       <li><p><var>window</var>'s <span data-x="concept-document-window">associated
+       <code>Document</code></span> is <span>allowed to use</span> the "<code
+       data-x="cross-origin-isolated-feature">cross-origin-isolated</code>" feature.</p>
+     </ol>
+     </dd>
+
     </dl>
    </li>
 
@@ -88664,7 +88680,20 @@ interface <dfn>ApplicationCache</dfn> : <span>EventTarget</span> {
    for="environment settings object">cross-origin isolated capability</dfn></dt>
 
    <dd><p>A boolean representing whether scripts that use this <span>environment settings
-   object</span> are allowed to use APIs that require cross-origin isolation.</p></dd>
+   object</span> are allowed to use APIs that require cross-origin isolation.</p>
+   <div class="note">
+     <p>
+       This value is platform dependent, because on some platforms is not possible to provide the
+       security properties associated with this state. There are platform independent invariants
+       though, it "MUST" be false whenever:
+     </p>
+     <ul>
+       <li><p>The surrounding agent cluster's cross-origin isolated is false</p></li>
+       <li><p>The corresponding feature policy doesn't allow to use the feature</p></li>
+     </ul>
+   </div>
+   </dd>
+
   </dl>
 
   <p>An <span>environment settings object</span> also has an <dfn>outstanding rejected promises