From 2b840752201cae0b1b95a39399bb93e513671049 Mon Sep 17 00:00:00 2001
From: Marcos Caceres <marcos@marcosc.com>
Date: Thu, 10 Aug 2017 14:53:48 +1000
Subject: [PATCH] Define generalized PMI validator

---
 index.html | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/index.html b/index.html
index e2e743e..7f85082 100644
--- a/index.html
+++ b/index.html
@@ -72,6 +72,27 @@ <h2>
           <a>standardized payment method identifier</a>.
         </li>
       </ul>
+      <section>
+        <h3>
+          Validity
+        </h3>
+        <p>
+          The steps to <dfn>validate a payment method identifier</dfn> with a
+          <var>pmi</var> string are given by the following algorithm. It
+          returns either a true or false.
+        </p>
+        <ol>
+          <li>Let <var>url</var> be the result of running the <a>basic URL
+          parser</a> with <var>pmi</var>.
+          </li>
+          <li>If <var>url</var> is failure, <a>validate a standardized payment
+          method identifier</a> with <var>pmi</var> and return the result.
+          </li>
+          <li>Otherwise, <a>validate a URL-based payment method identifier</a>
+          passing <var>url</var> and return the result.
+          </li>
+        </ol>
+      </section>
     </section>
     <section>
       <h2>
@@ -194,10 +215,6 @@ <h2>
           the purpose of standardization, be sure that it conforms to the
           following regular expression: <code>[a-z0-9-]+</code>.
         </p>
-        <p>
-          User agents MUST NOT enforce validity or well-formedness of
-          <a>standardized payment method identifiers</a>.
-        </p>
         <div class="note">
           <p>
             When used in an API, the following method identifiers are all