From Halopedia, the Halo wiki
HCS Spotlight was a multiplayer event held for Halo Infinite. It was held between December 14 and December 20, 2021 during Season 01: Heroes of Reach. The event, unlike Fractures: Tenrai, Cyber Showdown, or Tactical Ops, had no specific unlock tree tied to it. Instead, the event offered unique challenges to players to commemorate the starting of the HCS Raleigh event, which were exclusive to Infinite's ranked playlist, but offered more XP for players.