N.Y. Comp. Codes R. & Regs. tit. 6 § 180.8
For the purposes of the Fish and Wildlife Law and this Title, a barbed broadhead shall be any arrowhead with a protrusion forming a hook, notch or backward point which impedes withdrawal of an arrow when the arrow is pulled from the flesh of an animal. The physical measurement which determines if a blade or other protuberance is barbed is the angle of the rear edge of the protuberance in relation to the arrow shaft or the forward projection of the arrow shaft. If the rear edge of the protuberance is perpendicular to the shaft, or angles forward as it progresses outward from the shaft, then the protuberance is not barbed. If any part of the rear edge of the protuberance angles toward the rear as it progresses outward from the shaft, then the broadhead is a barbed broadhead. Notwithstanding the above definition, a protuberance which appears to form a barb, but freely swings forward to a nonbarbed position upon withdrawal of the arrow shall not be considered a barb; and a notch at the base of a blade extending no more than two millimeters from the shaft shall not be considered a barb.
N.Y. Comp. Codes R. & Regs. Tit. 6 § 180.8