If you mean the loops of grossgrain, then they're just extra attachment points. You can use them if you're having a hard time getting a good fit. I use the ones between the ends to pull up the middle of the UQ and attach it to my whoopies at the end (see my gallery).
You can also use them with Dutch's UQ hooks, or sew attachment points to your hammock. I used one on my WBBB to hold the UQ above the footbox.