Example for Checkpoint
Because of the difficulty in keeping alternative pages up to date with the full content of the original page, alternative pages should be provided only after you have tried all of the other pertinent techniques outlined in the Web Content Accessibility Guidelines to make your original page accessible (unless the alternative page is automatically generated from the same source as the original page).
Here is one way you might give visitors the choice:
When the user chooses a link, the appropriate page will be served.
Please remember that this checkpoint should only be used as a LAST RESORT. As more browsers support the latest versions of HTML, XML, CSS1 and 2 and other accessible W3C languages, pages that cannot be made accessible by following the other guidelines will become rarer.