CSM are usually the ones with horns on the helmets (not always though). In the meantime you could make use of the "spot" function. So when you spot an enemy or a group of enemies they get clearly marked by a target symbol over their head. It could not only help you but also your allies, which also see the target symbol and get the enemies appear on their mini map...in case of they get dealt with shortly after you also get a spot assist XP bonus. Only drawback is that it doesn't always trigger so I usually spam the spot button until you hear and see a response.