Create Web documents that are well-formed
Make sure HTML tags are nested according to the specification
Browsers and other user agents, including assistive technologies, can accurately interpret and parse HTML content as long as they are well-formed, meaning that the elements are nested according to the rules set in the HTML specification. The goal is to avoid parsing errors that will potentially cause assistive technologies and other user agents to inaccurately interpret the markup and lead to misleading or false information due to markup not being structured as expected.
To do this, simply make sure that user agents, including assistive technologies, [...]