The first draft of the script (dated 20 April1967) described this vessel as the freighter "UES Larkin", under the command of Captain Robinson.
In the second and third editions of the Star Trek Encyclopedia, the Carolina was identified as an old Daedalus-class starship with either the registry number NCC-235 on page 66 or NCC-160 in the ship list on page 417. This was despite the fact that Daedalus-class had been retired from service seventy-one years earlier, as stated in TNG: "Power Play". In the latest Star Trek Encyclopedia (4th ed., Volume Two M-Z, p. 327), NCC-160 was changed in the ship list to NCC-235 and the class was not mentioned. However, on page 122, there was a picture of the Daedalus-class Carolina.