Agal[1] (garment) length of cord which is used to bind the kaffiyeh  to the head of the wearer, usually several loops secure it. The kaffiyeh is the head covering of the tribesmen of the Tahari, a folded, squarish cloth.

Samos turned away from the girl. He indicated to me a man who sat at a far end of one of the low tables. He did not drink wine or paga. The man, rare in Port Kar, won the kaffiyeh and agal. The kaffiyeh is a squarish scarf, folded over into a triangle, and placed over the head, two points at the side of the shoulders, one in back to protect the back of the neck. It is bound to the head by several loops of cord, the agal. The cording indicates tribe and district. 
To my right were the lines of the Aretai. The Aretai themselves, of course, with black kaffiyeh and white agal cording, held their center. 
Book 10, Tribesman: pg 307
see also