I will describe official rear sight use, as it is explained in Yugoslav People's Army M59/66 Field Manual. Numbers 1 to 10 are used for distances from 100 to 1000 meters (1 m = 1.093 yd). Rear "battle" notch has the same height as 300 meter notch and is used when there is no time for range adjustment. When using battle notch on targets up to 300 meters, POA should be in the middle of the target and when targets are at distances beyond 300 meters, POA should be on the top of the target. When engaging prone targets, POA should be at the bottom angle of the target.
Official Army zeroing was done this way: 4 rounds were shot at distance of 100 meters, using no. 3 sight notch. Target was 1 meter high and 0.5 meter wide (approx. 40 x 20 in) with black rectangle in the middle, measuring 25 x 20 centimeters (approx. 10 x 8 in). POA was in the middle of black rectangle's lower side with reference point in the middle of black rectangle's upper side. Rifle was considered zeroed if 3 of 4 rounds were inside 15 cm diameter (6 in), with centre of this three rounds not further than 5 cm (2 in) from reference point - middle of black rectangle's upper side.