The scene where the Enterprise NX-01 leaves the drydock reused the footage
The characters of Commander Williams, Admiral Leonard, and Admiral Forrest were named after three original Trek actors - William Shatner (James T. Kirk), Leonard Nimoy (Spock), and DeForest Kelley (Leonard H. McCoy). The Vulcan character 'Tos' was named after TOS - a popular acronym for The Original Series.
Zefram Cochran appears on a video recording.
Picard speaks of a tragic first contact encounter with the Klingons. In Broken Bow, that story is told in full.
Events mentioned in dialogue.
Events discussed in dialogue.
Trip Tucker makes reference to scratching the hull in an inspection pod a year earlier.
Admiral Cornwell says that the Discovery will be the first Federation ship in nearly one hundred years to visit Qo'noS, since Captain Archer and the Enterprise visited the Klingon home world in 2151.
A clip from this episode is shown.