Retrofitted dorsal carrier

From Memory Alpha, the free Star Trek reference

The retrofitted dorsal carrier was a type of starship built in the far future. The design number XRT-550 was connected to this carrier, with at least one commissioned in the year 3125.

It appeared in the temporal observatory owned by Daniels. (ENT: "Future Tense")

This information was shown next to the future Vulcan cruiser and the time travel pod on the observatory, and it is unclear if it referred to either of these ships.