Priority 1 Item 19
If you cannot create an accessible page, provide a link to
an alternative page that is accessible, has equivalent information
(or functionality), and is updated as often as the inaccessible (original)
page.
Recommended.
If it is impossible to create an equally accessible web page, provide a link
to another page, which is universally accessible and is built with technologies
endorsed by the World Wide Web Consortium (W3C). This page should provide
the same information or functionality as the inaccessible page but in an
accessible format. Changes to content or functionality should be made to
both pages simultaneously.