Third and final appearance of Deanna Troi within the "Voyager" series.
The Ferengi mention a ship with a metaphasic shield. This technology was developed by a Ferengi, Dr. Reyga, in the TNG episode "Suspicions."
Reg refers to the Romulans been interested in Voyager for years. This is likely a reference back to season 1 episode "Eye of the needle" when Voyager made contact with a Romulan captain from the past and passed messages and information along so he could pass this along in the future. The Romulans being so secretive meant they never shared this information with Starfleet.
The Doctor asks Reginald to join him for golf on the "back nine on Giedi Prime." Giedi Prime is a planet in Frank Herberts Dune universe previously mentioned in Drive (2000).
The dress worn by Leosa was worn by Fenna in DS9: "Second Sight" and by Antonia in Star Trek Generations.