The center rafter does similar, but has a "T" on the end. The horizontal bar runs thru the elbo perhaps 10" or so. The small tabs with the black paracord connected provides a few necessary things. One, when you are alone pulling the awning into the Keder rail, , the frame is not overly rigid prior to the ball bungees being installed. So, the paracord helps maintain rigidity and square until it is. Additionally, the Paracord gives more more "clothesline" to hang things on to dry.