The Zombie: Using <br> or for spacing (instead of CSS)
Always a Zombie? Pretty Much
Severity: Medium to Low, while it can make your site look terrible, the content is accessible and available.
Why is it a Zombie: Particularly with so many different screen sizes, it’s unlikely that many, if any, users will look at the website at the exact width you’re using when you build the site. Those that do will see your awesome website at its best. The other 99.99% of your visitors will see a formatting disaster of apocalyptic proportions.
Cure the Zombie by: Except for things like addresses and poetry, remove all formatting done with line breaks and non-breaking spaces. HTML’s natural line wrapping will determine line length based on the width of the containing/parent element so setting the width to your preferred line length (and, of course, modifying it for smaller screens) is your best bet.