Trivia: The ship we see Jack on in Salazar's flashback is called the Wicked Wench. This is a bit of an in-joke for PotC buffs, because that was the original name of the Black Pearl before being sunk by Cutler Beckett and raised again by Davy Jones. It's fully explained in a deleted scene of At World's End.
Trivia: When the British soldier tells Jack that guillotine is the new surprise way of being executed, he says guillotine sounds French, then says that the French invented mayonnaise. This is just like a deleted scene in the first PotC movie, Curse of the Black Pearl, when Jack is about to be shot and tries to say Parlay, then rambles on about the French, saying that they invented mayonnaise.
Trivia: Spoilers. Before the film was released, co-star Orlando Bloom confused some fans by referring to the film as both a sequel and a "soft reboot," making some think that the film was ignoring previous installments or was only going to focus on Jack Sparrow exclusively. When the film was released, it was revealed that he was actually cryptically referring to the fact that there were some shake-ups to the cast, as his character Will Turner is freed from his curse and thus could return from future films, Keira Knightly is re-introduced after being absent in the fourth film and the character of Hector Barbossa is given a hero's exit when he sacrifices himself.