The nock is A notch in the rearmost end of the arrow. It serves to keep the arrow in place on the string as the bow is being drawn. Nocks may be simple slots cut in the B of the arrow, or separate pieces made from wood, plastic, or horn that are then attached to the end of the arrow. Modern nocks, and traditional Turkish nocks, are often constructed so as to curve around the string or even C it slightly, so that the arrow is unlikely to slip off. In English it is common to say "nock an arrow" when one readies a shot.
In Arab archery, there was the description of the use of "nockless arrows". In shooting at the enemies, either the Turks or the Persians, it was seen that the enemies would pick up the expended arrows and shoot them back at the Arabs. So they developed "nockless arrows", which would be useless to their foes. The bowstring would have a small ring that is tied onto the string at the proper point where the nock would normally be placed. The end of the arrow, rather than being slit for a nock, would be sharpened like an arrowhead, then the rear end of the arrow would be slipped into this ring and drawn and released as usual. Then the enemy could collect all the arrows they wanted, but they would be useless to them in shooting back. A piece of advice was in battle, to have D rings tied onto the bowstring in case one broke.
FTF: LewisClan77