The Fleeting Order is a single-use Order token that can be used as a wildcard for any of Crew Order, Navigation Order and Artillery Order.
Order
The standard actions a player can make usually requires spending Order tokens. There are four types of Order: Crew Order, Navigation Order, Artillery Order, and also Fleeting Order which is a single-use wildcard that can be used as if it were any of the other three types.
A player can make any number of actions on their turn as long as they have Order tokens to spend. Spending an order moves it from the Fresh Orders area on a player's Ship Board to the Issued Orders area.
Order tokens are refreshed at the beginning of the Player Phase, but by default, each player normally only gets to refresh three Order tokens each Round, although some Traits and other effects may modify that number.
At the End of an Act, if the players "won" the Act by being first to the End of Act space on the Discovery Track, each player gets to choose one new Order token from the supply, and add to their Fresh Orders area.