diff --git a/index.html b/index.html
index b70f0ad2..61c796ae 100644
--- a/index.html
+++ b/index.html
@@ -616,6 +616,13 @@ <h2>
             "<a>AbortError</a>" <a>DOMException</a>.
           </p>
         </div>
+        <p>
+          The following algorithm provides an <dfn>extension point</dfn>: other
+          specifications that define more specific algorithms for matching the
+          available <a>payment apps</a> to the provided <a>payment methods</a>
+          are encouraged to hook themselves into this specification at this
+          point in the algorithm.
+        </p>
         <p>
           The <a>show()</a> method MUST act as follows:
         </p>
@@ -665,17 +672,22 @@ <h2>
           <li>Return <var>acceptPromise</var> and perform the remaining steps
           <a>in parallel</a>.
           </li>
-          <li>For each <var>paymentMethod</var> in
-          <var>request</var>.<a>[[\serializedMethodData]]</a>:
-            <ol>
-              <li>Determine which <a>payment apps</a> support any of the
-              <a>payment method identifiers</a> given by the first element of
-              the <var>paymentMethod</var> tuple. For each resulting payment
-              app, if payment method specific capabilities supplied by the
-              payment app match those provided by the second element of the
-              tuple, the payment app matches.
-              </li>
-            </ol>
+          <li>
+            <p>
+              <a>Extension point</a>: process algorithms for determining the
+              available methods of paying at this point.
+            </p>
+            <p>
+              The algorithms should process each item in
+              <var>request</var>.<a>[[\serializedMethodData]]</a> and determine
+              the set of <a>payment apps</a>, with the appropriate
+              capabilities, that is available to fulfill the payment request.
+            </p>
+            <p>
+              The output of executing these algorithms is a list of <a>payment
+              apps</a>, and any other methods of paying, able to fulfill the
+              payment request.
+            </p>
           </li>
           <li>If this consultation produced no supported method of paying, then
           reject <var>acceptPromise</var> with a "<a>NotSupportedError</a>" <a>
@@ -685,12 +697,11 @@ <h2>
           <li>
             <p>
               Otherwise, show a user interface to allow the user to interact
-              with the payment request process, using those <a>payment apps</a>
-              and <a>payment methods</a> which the above step identified as
-              feasible. The user agent MAY show payment methods in the order
-              given by <var>supportedMethods</var>, but SHOULD prioritize the
-              preference of the user when presenting payment methods and
-              applications.
+              with the payment request process, using those methods of paying
+              which the above step identified as supported. The user agent MAY
+              show these methods of paying in the order given by
+              <var>supportedMethods</var>, but SHOULD prioritize the preference
+              of the user.
             </p>
             <p>
               The <a>payment app</a> should be sent the appropriate data from