Smart-linking is the process of linking a telescopic sight to the user's heads-up display, however it has recently been also used to link other weapons without telescopic sights. It is used by the UNSC. Smart-links share data with many protocols integrated into a UNSC Marine Corps personnel's battle uniform by relaying information between various elements of a user's HUD, such as the motion sensor or the targeting reticle. The target reticle can recognize and distinguish allies and hostiles.