This adds extra room below your hips.

> This option exists to prevent belly fluff.
> 
> What's belly fluff? It's when you tuck your shirt in your trousers, and the part below the last button tend to creep open a bit,
> exposing part of your belly.

> If you're on a mission against belly fluff, you might also look into the <strong>button free length</strong> option.