corner case

Noun

 * 1)  A problem or situation that occurs only when two or more operating parameters are at extreme values, or when two or more unusual operating circumstances happen to coincide.
 * 2) * 2001, Faisal I. Haque, Khizar A. Khan, Jonathan Erik Michelson, The Art of Verification with Vera, Verification Central LLC
 * The smallest and largest legal packet sizes are examples of the first type of corner case. This type of boundary condition is usually specified by or easily inferred from the externally published feature set of the design.
 * 1)  Any unusual scenario.
 * 1)  Any unusual scenario.
 * 1)  Any unusual scenario.