Covenant fringe

The Covenant fringe is a term regarding the collection of alien species scattered throughout the Orion Arm of the Milky Way that were never completely integrated into the Covenant Hegemony. Member species like the Yonhet were not considered full signatories to the Covenant due to their small population. These alien races loyally provided various strategic and infrastructure-related advantages to the Covenant empire but never posed any real military threat. Focusing their efforts to reconstruction and exploration at the end of the Human-Covenant War, the Office of Naval Intelligence and the UNSC began to gather the first bits of intelligence on the exact nature and size of the Fringe.

Trivia
In reference to regular questions about the Covenant fringe on the Halo Waypoint forums, 343 Industries' 2015 April Fools included the full list of species that made up the fringe: the Yonhet, the Glacius (Killer Instinct), the Locust (Gears of War), and the Piñata (Viva Piñata).

List of appearances

 * Halo: Escalation
 * Halo: Nightfall