Shared with you
Military ranks used in Star Trek are all based upon actual military ranks. Starfleet ranks are those of the US Navy: Ensign, Lieutenant Junior Grade, Lieutenant, Lieutenant Commander, Commander, Captain, Commodore, Rear Admiral, Vice Admiral, and Admiral. Bajoran ranks are the same as those used in the U.S. Army, Air Force, and Marines: Lieutenant, Major, Lieutenant Colonel (or, as the Bajorans call it, "Field Colonel"), Colonel, and General. (Kira, after her promotion, was referred to simply as "Colonel", but she was promoted two steps in rank at once.) Klingon ranks are "bekk" (an enlisted rating), Ensign, Lieutenant, Commander, Captain, Colonel, Brigadier, General, and Admiral. Cardassian ranks are based on those of the ancient Roman Empire: Gil (equivalent to a Starfleet/U.S. Naval Lieutenant), Glinn (Commander), Gul (Captain), and Legate (Admiral).
Kira was a last-minute addition to the cast. The original plan was to include the Star Trek: The Next Generation (1987) character of Ro Laren, but Michelle Forbes didn't want to do a series at the time.
Although we only rarely see it, there is an ATM in Quark's bar. It dispenses the various types of currency used by major races visiting the station: Federation credits, Bajoran litas, Cardassian leks, and Ferengi latinum.
Colm Meaney was initially reluctant about signing onto the series. Meaney was comfortable playing O'Brien on an episode by episode basis for Star Trek: The Next Generation (1987), and at the time, was unsure if he wanted to play a full time television role.
Armin Shimerman (Quark) and Marc Alaimo (Gul Dukat the Cardassian) appeared as one of the first actors to portray members of their respective species, and both appeared on Star Trek: The Next Generation (1987). Shimerman played the Ferengi officer Letek in The Last Outpost (1987) while Alaimo played the Cardassian officer Gul Macet in The Wounded (1991).
Michael Dorn did not want to reprise his role as Worf, since the daily make-up application was exhausting, and he was relieved to be able to move on. Dorn said that the salary he was offered made him reconsider.