My forearm grip/hand protector is a MOE with the little slots for attaching accessories. I know most of these are "picatinny" for mounting things like lights, lasers, vertical grips, etc. What would mine be considered when I look to purchase accessories. The following link shows a vertical grip that would be mounted to my style of rail, but most are not like this. I'm just looking for the name of this style of mounting system. Thanks.
Amazon.com: Magpul MOE MVG Grip, Black: Sports & Outdoors