Example for Checkpoint
10.3 - Until user agents render side-by-side text correctly provide a linear text alternative (on the current page or some other) for all tables that lay out text in parallel, word-wrapped columns.

Here, "user agents" also include assistive technologies.

The text in the following columns will wrap differently depending on the font size, window size, and screen resolution you have selected:

Chapter 1 It was a dark and stormy night, and all through the house the literary critics were honing their red pencils to attack the unsuspecting author who started a story with "It was a dark and stormy night...".

Chapter 2 Suddenly a shot rang out, then a shout, then a thump, then the sound of a car door slamming on someone's thumb.

Chapter 3 Then the inspector cried, "I know who did this dastardly deed and I will reveal the perpetrator's identity this very evening, in this very room!"

Conclusion And they lived happily ever after, secure in the knowledge that their secret was safe. The End

Users of some screen-readers would hear something like this:

Chapter 1 Chapter 2 Chapter 3 Conclusion, It was a dark and suddenly a shot rang then the inspector and they lived happily stormy night, and all out, then a shout, then cried, I know who did ever after secure in...

I realize that in this case the latter may actually better literature than the original, but you get the drift.

To Checkpoints for Guideline 10.