diff --git a/index b/index
index f29233c7515..24fbfd3b509 100644
--- a/index
+++ b/index
@@ -27224,24 +27224,29 @@ interface <dfn id=htmloptionelement>HTMLOptionElement</dfn> : <a href=#htmleleme
 
   <h5 id=enabling-and-disabling-form-controls><span class=secno>4.10.13.2 </span>Enabling and disabling form controls</h5>
 
-  <p class=XXX>... <dfn id=concept-fe-disabled title=concept-fe-disabled>disabled</dfn></p>
-  <!-- XXX remember to check for a fieldset ancestor that has its
-  disabled attribute set, and always be disabled if you find one -->
+  <p>The <dfn id=attr-fe-disabled title=attr-fe-disabled><code>disabled</code></dfn>
+  content attribute is a <a href=#boolean-attribute>boolean attribute</a>.</p>
 
-  <p class=XXX>... <dfn id=attr-fe-disabled title=attr-fe-disabled>disabled</dfn> content attribute</p>
-
-  <p class=XXX>... <dfn id=dom-fe-disabled title=dom-fe-disabled>disabled</dfn> DOM attribute</p>
+  <p>A form control is <dfn id=concept-fe-disabled title=concept-fe-disabled>disabled</dfn>
+  if its <code title=attr-fe-disabled><a href=#attr-fe-disabled>disabled</a></code> attribute is
+  set, or if it is a descendant of a <code><a href=#the-fieldset-element>fieldset</a></code> element
+  whose <code title=attr-fieldset-disabled><a href=#attr-fieldset-disabled>disabled</a></code> attribute
+  is set.</p>
 
   <p><strong>Constraint validation:</strong> If an element is <a href=#concept-fe-disabled title=concept-fe-disabled>disabled</a>, it is <a href=#barred-from-constraint-validation>barred from
   constraint validation</a>.</p>
 
+  <p>The <dfn id=dom-fe-disabled title=dom-fe-disabled><code>disabled</code></dfn> DOM
+  attribute must <a href=#reflect>reflect</a> the <code title=attr-fe-disabled><a href=#attr-fe-disabled>disabled</a></code> content attribute.</p>
+
 
 
   <h5 id="a-form-control's-value"><span class=secno>4.10.13.3 </span>A form control's value</h5>
 
-  <p class=XXX>... <dfn id=concept-fe-value title=concept-fe-value>value</dfn></p>
-  <p class=XXX>... <dfn id=concept-fe-checked title=concept-fe-checked>checkedness</dfn></p>
-  <!-- XXX autocomplete: define somewhere that the value may be set from a stored value -->
+  <p>Form controls have a <dfn id=concept-fe-value title=concept-fe-value>value</dfn>
+  and a <dfn id=concept-fe-checked title=concept-fe-checked>checkedness</dfn>. (The latter
+  is only used by <code><a href=#the-input-element>input</a></code> elements.) These are used to
+  describe how the user interacts with the control.</p>
 
 
 
diff --git a/source b/source
index 3cbbe8c892f..dd46c60681b 100644
--- a/source
+++ b/source
@@ -30569,25 +30569,31 @@ interface <dfn>HTMLOptionElement</dfn> : <span>HTMLElement</span> {
 
   <h5>Enabling and disabling form controls</h5>
 
-  <p class="XXX">... <dfn title="concept-fe-disabled">disabled</dfn></p>
-  <!-- XXX remember to check for a fieldset ancestor that has its
-  disabled attribute set, and always be disabled if you find one -->
+  <p>The <dfn title="attr-fe-disabled"><code>disabled</code></dfn>
+  content attribute is a <span>boolean attribute</span>.</p>
 
-  <p class="XXX">... <dfn title="attr-fe-disabled">disabled</dfn> content attribute</p>
-
-  <p class="XXX">... <dfn title="dom-fe-disabled">disabled</dfn> DOM attribute</p>
+  <p>A form control is <dfn title="concept-fe-disabled">disabled</dfn>
+  if its <code title="attr-fe-disabled">disabled</code> attribute is
+  set, or if it is a descendant of a <code>fieldset</code> element
+  whose <code title="attr-fieldset-disabled">disabled</code> attribute
+  is set.</p>
 
   <p><strong>Constraint validation:</strong> If an element is <span
   title="concept-fe-disabled">disabled</span>, it is <span>barred from
   constraint validation</span>.</p>
 
+  <p>The <dfn title="dom-fe-disabled"><code>disabled</code></dfn> DOM
+  attribute must <span>reflect</span> the <code
+  title="attr-fe-disabled">disabled</code> content attribute.</p>
+
 
 
   <h5>A form control's value</h5>
 
-  <p class="XXX">... <dfn title="concept-fe-value">value</dfn></p>
-  <p class="XXX">... <dfn title="concept-fe-checked">checkedness</dfn></p>
-  <!-- XXX autocomplete: define somewhere that the value may be set from a stored value -->
+  <p>Form controls have a <dfn title="concept-fe-value">value</dfn>
+  and a <dfn title="concept-fe-checked">checkedness</dfn>. (The latter
+  is only used by <code>input</code> elements.) These are used to
+  describe how the user interacts with the control.</p>