From Halopedia, the Halo wiki
During the Fall of Reach, Dragon X-ray, radioed in Blue-Delta, who appears to be associated with HIGHCOM, for assistance. Blue-Delta warned X-ray that his unit was the only UNSC asset in the area, meaning that any support would take a while to arrive. X-ray was unable to hear Blue-Delta's response due to enemy movement, to which Blue-Delta warned him again. X-ray acknowledged receiving the warning and reported movement again, requesting for support to "soften them up". After being asked for the location of the enemy forces, Dragon X-ray responded and gave him the grid co-ordinates.
Requesting for support again, Blue-Delta told Dragon X-ray that there was no available support in any way apart from the UNSC Aegis Fate. Dragon X-ray inquired whether the Aegis Fate was a space-borne or an ocean-borne vessel, to which Blue-Delta answered that the Aegis Fate was a Frigate-designated "Exo-asset". The conversation ended with Dragon X-ray reporting being less than a klick away from the objective, and Blue-Delta wishing him good luck.
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