V-cut ground electrodes are called a variety of names depending on manufacturer. Although they look similar, they may be called a tapered cut ground, trimmed side electrode, wedge shaped ground, v-trimmed electrode, inverted v-tip ground, v-power (NGK) or U-groove (Denso). So what's the point? The v-cut give the flame a groove to grow in and forces the spark to the outer edge of the ground electrode - placing it close to the air/fuel mixture and creating a larger flame that ignites quicker for a more complete combustion, even in the case of lean air/fuel mixture. A conventional, flat ground electrode design of regular plugs crushes the flame (sometimes called quenching), thereby preventing full spark potential.