Hardpoint

A hardpoint is a point on the outer hull of a warship where another vessel of similar size and density may dock and link systems. These points can be used to combine engine power, telemetry, stabilize, and link computer or AI systems.

Background
Newer UNSC warships have these hard points on their dorsal and ventral sides, in case the ship was too crippled to move under its own power. Another UNSC vessel could then use its own hard points to dock with the wounded ship, link systems and carry it away (presumably to a repair platform or safe zone).

Some Covenant ships also have hard points that can be used by a ship too large to fit inside one of the docking bays, like the Phantom.

Trivia
They are first mentioned in Halo: First Strike, when Cortana used the captured Covenant Flagship Ascendant Justice to dock with the disabled and abandoned. Since Covenant and UNSC systems are incompatible, Cortana used the Gettysburg's service drones and the Ascendant Justice's Engineers to adapt their power uplinks.

List of appearances

 * Halo: First Strike
 * Halo: Reach