Contentinfo landmark should not be contained in another landmark
How to Fix the Problem
  Ensure any contentinfo landmark is not be contained in another
  landmark.
  Text content should be contained within a landmark region, the
  role="contentinfo" ARIA landmark should be used on an element
  that is outside of other landmarks used on the page, since footer information
  is generally separated from the header and main body content.
Why it Matters
  The purpose of the contentinfo landmark can be defeated when
  placed within another landmark, as it can prevent blind screen reader users
  from being able to quickly find and navigate to the appropriate landmark.
  When screen reader users have to sort through too much extra information to
  find what they're looking for, such as not being able to quickly figure out
  which landmark contains the content information they're looking for negates
  the purpose of an existing contentinfo landmark.
Rule Description
Contentinfo landmark must be at top level.
The Algorithm (in simple terms)
This rule finds the elements for the footer:not([role]) and [role="contentinfo"] selectors, then checks to see if the landmark has a body context.
 
              

