Information we read on the web appears in certain visual structures. We know a navigation is a navigation just by looking at it. What about people without sight? How would they know if they have focussed a navigation block, or if the number they are hearing is a telephone number?
To help these users we add hidden descriptive texts to the page. We do
this by creating a class named
implicit. This class will then
hide content that can be classified as implicit. Take look at the
class definition below.
height properties are set to
1px, a value of
0 will cause the content to not
be read on some screen readers. It’s positioned
absolute so it will not affect
page flow. Combined with the other properties this will result in a
box that is effectively zero × zero pixels big.
This is how you would use this
implicit class in your HTML.
These implicit elements are now hidden but are still read by screen readers. People using assistive technologies now have a little bit of extra context to make it easier to understand the content.
As a bonus, this additional information will also benefit search engines.