diff --git a/index.html b/index.html
index c1be70af..50e6c626 100644
--- a/index.html
+++ b/index.html
@@ -1933,7 +1933,7 @@ <h2>
           localities.
         </dd>
         <dt>
-          <dfn>Postal code</dfn>
+          <dfn data-lt="Postal codes">Postal code</dfn>
         </dt>
         <dd>
           The postal code or ZIP code, also known as PIN code in India.
@@ -1990,6 +1990,7 @@ <h2>
             readonly attribute DOMString postalCode;
             readonly attribute DOMString recipient;
             readonly attribute DOMString region;
+            readonly attribute DOMString regionCode;
             readonly attribute DOMString sortingCode;
             readonly attribute FrozenArray&lt;DOMString&gt; addressLine;
           };
@@ -2010,10 +2011,11 @@ <h2>
           </p>
           <ol data-link-for="AddressInit">
             <li>Let <var>address</var> be a new instance of
-            <a>PaymentAddress</a>.
-            </li>Set <var>address</var>.<a>[[\addressLine]]</a>to the empty
-            frozen array, and all other <a data-lt=
-            "PaymentAddress slots">internal slots</a>set to the empty string.
+            <a>PaymentAddress</a>.Set
+            <var>address</var>.<a>[[\addressLine]]</a>to the empty frozen
+            array, and all other <a data-lt="PaymentAddress slots">internal
+            slots</a>set to the empty string.
+            </li>
             <li>If <var>details</var> was not passed to the constructor, return
             <var>address</var> and terminate this algorithm.
             </li>
@@ -2023,7 +2025,7 @@ <h2>
                 "!INFRA#ascii-uppercase">ASCII uppercasing</a>
                 <var>details</var>["<a>country</a>"].
                 </li>
-                <li>If <var>country</var> is not a valid [[!ISO3166]] alpha-2
+                <li>If <var>country</var> is not a valid [[!ISO3166-1]] alpha-2
                 code, throw a <a>RangeError</a> exception.
                 </li>
                 <li>Set <var>address</var>.<a>[[\country]]</a> to
@@ -2031,6 +2033,20 @@ <h2>
                 </li>
               </ol>
             </li>
+            <li>If <var>details</var>["<a>regionCode</a>"] is present:
+              <ol>
+                <li>Let <var>regionCode</var> be the result of <a data-cite=
+                "!INFRA#ascii-uppercase">ASCII uppercasing</a>
+                <var>details</var>["<a>regionCode</a>"].
+                </li>
+                <li>If <var>regionCode</var> is not a valid [[!ISO3166-2]]
+                subdivision code, throw a <a>RangeError</a> exception.
+                </li>
+                <li>Set <var>address</var>.<a>[[\regionCode]]</a> to
+                <var>regionCode</var>.
+                </li>
+              </ol>
+            </li>
             <li>If <var>details</var>["<a>phone</a>"] is present:
               <ol>
                 <li>If <var>details</var>["<a>phone</a>"] is not a
@@ -2127,7 +2143,8 @@ <h2>
             <dfn>addressLine</dfn> attribute
           </h2>
           <p>
-            When getting, returns the value of the <a>PaymentAddress</a>'s
+            Represents the <a>address line</a> of the address. When getting,
+            returns the value of the <a>PaymentAddress</a>'s
             <a>[[\addressLine]]</a> internal slot.
           </p>
         </section>
@@ -2136,8 +2153,19 @@ <h2>
             <dfn>region</dfn> attribute
           </h2>
           <p>
-            When getting, returns the value of the <a>PaymentAddress</a>'s
-            <a>[[\region]]</a> internal slot.
+            Represents the <a>region</a> of the address. When getting, returns
+            the value of the <a>PaymentAddress</a>'s <a>[[\region]]</a>
+            internal slot.
+          </p>
+        </section>
+        <section>
+          <h2>
+            <dfn>regionCode</dfn> attribute
+          </h2>
+          <p>
+            Represents the <a>region</a> of the address as an [[!ISO3166-2]]
+            code. When getting, returns the value of the
+            <a>PaymentAddress</a>'s <a>[[\regionCode]]</a> internal slot.
           </p>
         </section>
         <section>
@@ -2145,8 +2173,9 @@ <h2>
             <dfn>city</dfn> attribute
           </h2>
           <p>
-            When getting, returns the value of the <a>PaymentAddress</a>'s
-            <a>[[\city]]</a> internal slot.
+            Represents the <a>city</a> of the address. When getting, returns
+            the value of the <a>PaymentAddress</a>'s <a>[[\city]]</a> internal
+            slot.
           </p>
         </section>
         <section>
@@ -2154,7 +2183,8 @@ <h2>
             <dfn>dependentLocality</dfn> attribute
           </h2>
           <p>
-            When getting, returns the value of the <a>PaymentAddress</a>'s
+            Represents the <a>dependent locality</a> of the address. When
+            getting, returns the value of the <a>PaymentAddress</a>'s
             <a>[[\dependentLocality]]</a> internal slot.
           </p>
         </section>
@@ -2163,7 +2193,8 @@ <h2>
             <dfn>postalCode</dfn> attribute
           </h2>
           <p>
-            When getting, returns the value of the <a>PaymentAddress</a>'s
+            Represents the <a>postal code</a> of the address. When getting,
+            returns the value of the <a>PaymentAddress</a>'s
             <a>[[\postalCode]]</a> internal slot.
           </p>
         </section>
@@ -2172,7 +2203,8 @@ <h2>
             <dfn>sortingCode</dfn> attribute
           </h2>
           <p>
-            When getting, returns the value of the <a>PaymentAddress</a>'s
+            Represents the <a>sorting code</a> of the address. When getting,
+            returns the value of the <a>PaymentAddress</a>'s
             <a>[[\sortingCode]]</a> internal slot.
           </p>
         </section>
@@ -2181,7 +2213,8 @@ <h2>
             <dfn>languageCode</dfn> attribute
           </h2>
           <p>
-            When getting, returns the value of the <a>PaymentAddress</a>'s
+            Represents the <a>language code</a> of the address. When getting,
+            returns the value of the <a>PaymentAddress</a>'s
             <a>[[\languageCode]]</a> internal slot.
           </p>
         </section>
@@ -2190,7 +2223,8 @@ <h2>
             <dfn>organization</dfn> attribute
           </h2>
           <p>
-            When getting, returns the value of the <a>PaymentAddress</a>'s
+            Represents the <a>organization</a> of the address. When getting,
+            returns the value of the <a>PaymentAddress</a>'s
             <a>[[\organization]]</a> internal slot.
           </p>
         </section>
@@ -2199,7 +2233,8 @@ <h2>
             <dfn>recipient</dfn> attribute
           </h2>
           <p>
-            When getting, returns the value of the <a>PaymentAddress</a>'s
+            Represents the <a>recipient</a> of the address. When getting,
+            returns the value of the <a>PaymentAddress</a>'s
             <a>[[\recipient]]</a> internal slot.
           </p>
         </section>
@@ -2208,8 +2243,9 @@ <h2>
             <dfn>phone</dfn> attribute
           </h2>
           <p>
-            When getting, returns the value of the <a>PaymentAddress</a>'s
-            <a>[[\phone]]</a> internal slot.
+            Represents the <a>phone</a> of the address. When getting, returns
+            the value of the <a>PaymentAddress</a>'s <a>[[\phone]]</a> internal
+            slot.
           </p>
         </section>
         <section data-link-for="">
@@ -2231,7 +2267,7 @@ <h2>
                 <dfn>[[\country]]</dfn>
               </td>
               <td>
-                A <a>country</a> as an [[!ISO3166]] alpha-2 code or the empty
+                A <a>country</a> as an [[!ISO3166-1]] alpha-2 code or the empty
                 string stored in its canonical uppercase form. For example,
                 "JP".
               </td>
@@ -2250,7 +2286,20 @@ <h2>
                 <dfn>[[\region]]</dfn>
               </td>
               <td>
-                A <a>region</a> or the empty string.
+                A <a>region</a> as a country subdivision name or the empty
+                string, such as "Victoria", representing the state of Victoria
+                in Australia.
+              </td>
+            </tr>
+            <tr>
+              <td>
+                <dfn>[[\regionCode]]</dfn>
+              </td>
+              <td>
+                A <a>region</a> as a [[!ISO3166-2]] subdivision code or the
+                empty string stored in its canonical uppercase form. For
+                example, "<code>PT-11</code>" represents the Lisbon district of
+                Portugal.
               </td>
             </tr>
             <tr>
@@ -2330,6 +2379,7 @@ <h2>
             DOMString country;
             sequence&lt;DOMString&gt; addressLine;
             DOMString region;
+            DOMString regionCode;
             DOMString city;
             DOMString dependentLocality;
             DOMString postalCode;
@@ -2350,7 +2400,7 @@ <h2>
             <dfn>country</dfn> member
           </dt>
           <dd>
-            A <a>country</a>.
+            An [[!ISO3166-1]] country code, representing the <a>country</a>.
           </dd>
           <dt>
             <dfn>addressLine</dfn> member
@@ -2364,6 +2414,12 @@ <h2>
           <dd>
             A <a>region</a>.
           </dd>
+          <dt>
+            <dfn>regionCode</dfn> member
+          </dt>
+          <dd>
+            An [[!ISO3166-2]] subdivision code representing the <a>region</a>.
+          </dd>
           <dt>
             <dfn>city</dfn> member
           </dt>
@@ -2431,6 +2487,7 @@ <h2>
             "postalCode",
             "recipient",
             "region",
+            "regionCode",
             "sortingCode"
           };
         </pre>
@@ -2439,9 +2496,9 @@ <h2>
           "<dfn>country</dfn>", "<dfn>dependentLocality</dfn>",
           "<dfn>languageCode</dfn>", "<dfn>organization</dfn>",
           "<dfn>phone</dfn>", "<dfn>postalCode</dfn>", "<dfn>recipient</dfn>",
-          "<dfn>region</dfn>", and "<dfn>sortingCode</dfn>" enum values
-          correspond to attributes with the same identifiers in the
-          <a>PaymentAddress</a> interface.
+          "<dfn>region</dfn>", "<dfn>regionCode</dfn>" and
+          "<dfn>sortingCode</dfn>" enum values correspond to attributes with
+          the same identifiers in the <a>PaymentAddress</a> interface.
         </p>
       </section>
       <section>
@@ -2470,7 +2527,7 @@ <h2>
           </li>
           <li>If "<a data-link-for="AddressField">country</a>" is not in <var>
             excludeList</var>, set <var>details</var>["<a>country</a>"] to the
-            user-provided country as an upper case [[!ISO3166]] alpha-2 code,
+            user-provided country as an upper case [[!ISO3166-1]] alpha-2 code,
             or to the empty string if none was provided.
           </li>
           <li>If "<a data-link-for="AddressField">phone</a>" is not in
@@ -2515,13 +2572,14 @@ <h2>
           <var>details</var>["<a>postalCode</a>"].
             <div class="note" title="Privacy of Postal Codes">
               <p>
-                <a>Postal codes</a> in certain countries can be so specific as to
-                uniquely identify an individual. This being a privacy concern,
-                some user agents only return the part of a postal code that they
-                deem sufficient for a merchant to calculate shipping costs. This
-                varies across countries and regions, and so the choice to redact
-                part, or all, of the postal code is left to the discretion of
-                implementers in the interest of protecting users' privacy.
+                <a>Postal codes</a> in certain countries can be so specific as
+                to uniquely identify an individual. This being a privacy
+                concern, some user agents only return the part of a postal code
+                that they deem sufficient for a merchant to calculate shipping
+                costs. This varies across countries and regions, and so the
+                choice to redact part, or all, of the postal code is left to
+                the discretion of implementers in the interest of protecting
+                users' privacy.
               </p>
             </div>
           </li>
@@ -2531,9 +2589,16 @@ <h2>
           string if none was provided.
           </li>
           <li>If "<a data-link-for="AddressField">region</a>" is not in
-          <var>excludeList</var>, set <var>details</var>["<a>region</a>"] to
-          the user-provided region, or to the empty string if none was
-          provided.
+          <var>excludeList</var>:
+            <ol>
+              <li>Set <var>details</var>["<a>region</a>"] to the user-provided
+              region, or to the empty string if none was provided.
+              </li>
+              <li>If <var>details</var>["<a>region</a>"] maps to a
+              [[!ISO3166-2]] subdivision code, set
+              <var>details</var>["<a>regionCode</a>"] to that subdivision code.
+              </li>
+            </ol>
           </li>
           <li>If "<a data-link-for="AddressField">sortingCode</a>" is not in
           <var>excludeList</var>, set <var>details</var>["<a>sortingCode</a>"]