title: autocomplete=new-password and making them confirm it via entering the password again
body: <p>html5 now has some new attribute values for the <code>autocomplete</code> attribute to assist user-agents when autofilling forms. One of the new values, <code>new-password</code>, is used to tell the user agent to enter a <strong>new</strong> password, opposed to the user's <strong>current</strong> password. </p>
  
  <p>What's not clear to me though, is <strong>how to properly tell it to generate the same password for both fields when your form makes the user enter the new password twice as a confirmation?</strong> Maybe by using the same custom <code>section-*</code> prefix on both inputs, such as <code>autocomplete="new-password section-my-new-pw"</code>? The spec mentions the <code>section-*</code> prefix will affect the <a href="https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#autofill-scope" rel="noreferrer">autofill scope</a>, but it's not overly specific about what that means for my case.</p>
  
  <p>Here's a sample form that I imagine will represent what many websites will soon use - it distinguishes the <code>current-password</code> from the <code>new-password</code>, and makes the user confirm the new password.</p>
  
  <pre><code>&lt;form&gt;
      &lt;p&gt;Username             &lt;input type="text"     autocomplete="username"         name="username"&gt;&lt;/p&gt;
      &lt;p&gt;Current Password     &lt;input type="password" autocomplete="current-password" name="current-password"&gt;&lt;/p&gt;
      &lt;p&gt;New Password         &lt;input type="password" autocomplete="new-password"     name="new-password"&gt;&lt;/p&gt;
      &lt;p&gt;Confirm New Password &lt;input type="password" autocomplete="new-password"     name="confirm-new-password"&gt;&lt;/p&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>I much prefer if answers reference a documentation opposed to observations about how current browsers or extensions behave.</p>