The colours of all stations when in knip are replaced by their diagonal's opposite, and peg distances are reversed as if the player was performing a reverse manoeuvre. In spoon, players cannot cross the river at all without use of at least two substantive rebounds, which must be declared beforehand.
Spoon can be exited by a triple return or a triple rebound without crossing the Circle Line. (IMCS Ref: Concepts and Definitions Vol 3 Pg 391 - 394; Rules 899, 1984 and 2331.)
Spoon is very sensitive to the game context; under certain circumstances it is a corruption of 'Spain'.