From Halopedia, the Halo wiki
The Zehar system is a star system within human space. It contains at least six planets, including Zehar VI. During the later years of the Human-Covenant War, the UNSC constructed a hidden network of facilities on the surface of this planet, intended as a fallback point for personnel and assets. Zehar VI and its two moons have become a source of interest for the UNSC, with several peculiar findings noted.
Originally, the planet where Waterfall is located was stated to be part of the "Zezar" system in a Canon Fodder post, which was also supported by displays found on the map during the Season 6 flighting of Halo: The Master Chief Collection. However, those same displays were changed to say "Zehar VI" by the time the season was released and Waterfall was officially added to the game. Despite this, "Zezar VI" could still be seen in shadow behind the "Zehar VI" text. As of Season 7, the screens identify the planet as Zehar VI, with the shadowed text being fixed to reflect this new name as well.
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