Designated marksmen vs. "snipers"?

Designated marksmen handle the same kind of duties,ie taking well-aimed shots at enemy leaders and other snipers or calling indirect fire and/or air support on a position he can better pinpoint with his optics, but in a vastly smaller scale. For instance, the sniper team might operate beyond the perimeter for days on end to get intel, but a designated marksman would not go outside the wire unless he was on a patrol with the rest of his element. He doesn't have the specialised training that a sniper gets in camoflage and concealment, stealth and tracking and woodlore. They don't really even get much training in shooting other than what they receive normally.