diff --git a/index.html b/index.html
index 9dad2e44..51c90988 100644
--- a/index.html
+++ b/index.html
@@ -1471,7 +1471,7 @@ <h2>
         <dfn>PaymentItem</dfn> dictionary
       </h2>
       <pre class="idl">
-        dictionary PaymentItem {
+        dictionary PaymentItem : Localizable {
           required DOMString label;
           required PaymentCurrencyAmount amount;
           boolean pending = false;
@@ -1487,8 +1487,8 @@ <h2>
           <dfn>label</dfn>
         </dt>
         <dd>
-          This is a human-readable description of the item. The <a>user
-          agent</a> may display this to the user.
+          A <a>localizable member</a> that represents the description of the
+          item. The <a>user agent</a> may display this to the user.
         </dd>
         <dt>
           <dfn>amount</dfn>
@@ -1646,7 +1646,7 @@ <h2>
         <dfn>PaymentShippingOption</dfn> dictionary
       </h2>
       <pre class="idl">
-        dictionary PaymentShippingOption {
+        dictionary PaymentShippingOption : Localizable {
           required DOMString id;
           required DOMString label;
           required PaymentCurrencyAmount amount;
@@ -1673,9 +1673,9 @@ <h2>
           <dfn>label</dfn>
         </dt>
         <dd>
-          This is a human-readable description of the item. The <a>user
-          agent</a> SHOULD use this string to display the shipping option to
-          the user.
+          A <a>localizable member</a> that represents the description of the
+          item. The <a>user agent</a> SHOULD use this string to display the
+          shipping option to the user.
         </dd>
         <dt>
           <dfn>amount</dfn>
@@ -2306,8 +2306,8 @@ <h2>
                         to <var>details</var>.<a>modifiers</a>.
                         </li>
                         <li>Set
-                        <var>request</var>.<a>[[\serializedModifierData]]</a> to
-                        <var>serializedModifierData</var>.
+                        <var>request</var>.<a>[[\serializedModifierData]]</a>
+                        to <var>serializedModifierData</var>.
                         </li>
                       </ol>
                     </li>
@@ -2813,6 +2813,11 @@ <h2>
           Web IDL
         </dt>
         <dd>
+          <p>
+            The concept of a <dfn>localizable member</dfn> and the
+            <code><dfn>Localizable</dfn></code> dictionary are defined by
+            [[!WEBIDL-LS]].
+          </p>
           <p>
             When this specification says to <dfn data-cite=
             "!WEBIDL-LS#dfn-throw" data-lt="throws">throw</dfn> an error, the