That is a the signal a mech has a NARC on it. No matter where it goes, no matter if it has another player targeting it or not. It IS targeted. It cant hide it cant run! The NARC lasts 20 seconds. Take advantage of it.
If you have a light NARCing for you be grateful. Take advantage and watch your damage SKY rocket. The payoff for a light NARCing is little to none. Yes they get xp/cb but its CRAP compared to the xp/cb they could be getting from out damaging your LRM boat.
NARC, its a good thing when its being shot from your team. Take advantage of it!





















