title: What does the dark triangle, located on the folder icons in Xcode 9, mean?
body: <p>I use Xcode 9.0. Some folders icons in my Xcode project have dark triangles in bottom left corner - for example, "0. Login", "Frameworks", "Products", "Pods". What does this mean? </p>
  
  <p><a href="https://i.stack.imgur.com/zjuIS.png" rel="noreferrer"><img src="https://i.stack.imgur.com/zjuIS.png" alt="Image with dark triangles on folders icons"></a></p>