From Halopedia, the Halo wiki
Operation: DELHI was an operation of the United Nations Space Command sometime between 2547 and August 2558 on the human Outer Colony of Hat Yai. The operation involved the denial of material to insurrectionist forces on Hat Yai, as UNSC forces destroyed twenty-one special technical assets belonging to the rebels at the operation's conclusion. ONI agent Jameson Locke participated in this operation.
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