To declare something spronk, it means that it is forbidden. Its first mentioning is when the book about "Fleckisa and Other Disorders of the Gizzard" is considered spronk by Dewlap . Soren and a few other owls make a plan to get Otulissa to ask the book matron to fetch it for her. Dewlap tells the spotted owl its spronk and stops the matron. After a small scuffle between Dewlap and Outilssa, the spotted owl screeches "sprink on your spronk!" causing Dewlap to faint.
Another mentioning is when Dewlap again tries to enforce the spronk of the book when she sees Otulissa reading it before First Light . The spronked book falls into the sea when again Otulissa curses Dewlap after nearly missing an impotant mission from doing her flint mop .
Eventually, Ezylryb finds the book in the water and uses his techniques to remake it.