|Location:||United Federation of Planets|
- You may be looking for the unrelated moon, Delta III.
In a parallel universe, Delta IV was a Federation planet that was the location of the first joint Borg/Cybermen attack against the Federation in 2368. The planet was overwhelmed in minutes, forcing its Prime Minister to order a planetary evacuation well before Starfleet's defensive task force could arrive. (COMIC: Assimilation²)