This is stolen from the title of a paper in a recent conference.
The paper was about Misuse Cases.

A MisuseStory spells out what should be done if a user
attempts to get into a UserStory but does something unexpected.
It is a parallel concept to the UML/Objectory idea of an Extended Use Case.

For example: if the UserStory is that the customer has asked to be able to
input a number like 13 and get the square 169 back. Then a MisuseStory
describes what to with input like "III" (output "IX"? reject with polite
message? ). 

The default is to treat misuse as erroneous.  However a system
can get more useful by adding functionality to handle misuse cases.
The resulting misuse story is just a UserStory.

The only value in the term Misuse Story is to encourage people to make
systems that do not reject mistakes but do good things in return.

Compare with a UserAntiStory.


--DickBotting