/in-ˌkan-ˈtā-shən/
n. Any particularly arbitrary or obscure command that one must mutter at a system to attain a desired result. Not used of passwords or other explicit security features. Especially used of tricks that are so poorly documented they must be learned from a wizard.
"This compiler normally locates initialized data in the data segment, but if you mutter the right incantation they will be forced into text space."