Delb II was the second planet of the Delb planetary system. It was the homeworld of Nellen Tore, an assistant to Admiral Norah Satie. (TNG: "The Drumhead")
Delb II appeared in the star chart Data and Picard were studying in Stellar Cartography in 2371. (Star Trek Generations, display graphic)
According to the Star Trek: Star Charts ("United Federation of Planets I"), Delb II was listed as a member planet of the Federation in 2378.