Add loyalty guidance for facilitating users switching UAs (#28)

SHA: 6450078
Reason: push, by csarven

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: csarven

index.html

@@ -8,7 +8,7 @@
   <meta content="Bikeshed version 1453201ca, updated Wed Nov 5 21:01:59 2025 +0000" name="generator">
   <link href="https://w3ctag.github.io/user-agents" rel="canonical">
   <link href="https://www.w3.org/2008/site/images/favicon.ico" rel="icon">
-  <meta content="4f23c1350abe8f4a414b19b76a73f33103a231f4" name="revision">
+  <meta content="645007840787ecbacb9c428e94b0e6696f1f9b3e" name="revision">
   <meta content="dark light" name="color-scheme">
   <link href="https://www.w3.org/StyleSheets/TR/2021/dark.css" media="(prefers-color-scheme: dark)" rel="stylesheet" type="text/css">
 <style>/* Boilerplate: style-autolinks */
@@ -574,7 +574,7 @@
 </p>
    <h1 class="no-ref p-name" id="title">Web User Agents</h1>
    <p id="w3c-state"><a href="https://www.w3.org/standards/types/#ED">Editor’s Draft</a>,
-    <time class="dt-updated" datetime="2025-11-05">5 November 2025</time></p>
+    <time class="dt-updated" datetime="2025-11-06">6 November 2025</time></p>
    <details open>
     <summary>More details about this document</summary>
     <div data-fill-with="spec-metadata">
@@ -780,6 +780,11 @@ <h3 class="heading settled" data-level="3.3" id="loyalty"><span class="secno">3.
    <p>A user agent can also help its user
 make a credible commitment to a page in order to get that page’s services,
 and it’s not disloyal to maintain that commitment after getting the services.</p>
+   <p>A user agent must not obstruct its users from switching to another user agent.
+For example, it must not block access to, export, or store user data in ways that prevent portability.
+This includes identity information, bookmarks, history, passwords, and credentials such as passkeys.
+If the user agent relies on the underlying <abbr title="Operating System">OS</abbr> to store credentials,
+there needs to be a way for users to allow other user agents to access those credentials.</p>
    <section class="non-normative">
     <h2 class="heading settled" data-level="4" id="acknowledgements"><span class="secno">4. </span><span class="content">Acknowledgements</span><a class="self-link" href="#acknowledgements"></a></h2>
     <p>Thanks to the <a data-biblio-display="inline" data-link-type="biblio" href="https://infra.spec.whatwg.org/"><cite>Infra Standard</cite></a>