Board Thread:News and Announcements/@comment-15636815-20131111185541/@comment-15636815-20131127103401

That's an idea, and it fits with something I read just now.

In addition to colour, I put the text in italics to give readers another way to know that those cells were special. However, screen readers for the visually impaired tend to ignore italics. Therefore, to be accessible, our page needs a different way of drawing attention to that information.

The MOS gave several ideas. My favourite is to use a template that produces an image with alt text. Wikipedia's Template:Smiley looks like a great solution. For example, we could use a "confused" smiley to represent unconfirmed data and a "sad" smiley to represent missing data. They attract visual attention without the harshness of bright backgrounds, and they solve the two biggest accessibility problems:  colour-blindness and compatibility with screen readers. What do you think?