  Edge casing is a well-known method to improve the readability of drawings of
non-planar graphs. A cased drawing orders the edges of each edge crossing and
interrupts the lower edge in an appropriate neighborhood of the crossing.
Certain orders will lead to a more readable drawing than others. We formulate
several optimization criteria that try to capture the concept of a "good" cased
drawing. Further, we address the algorithmic question of how to turn a given
drawing into an optimal cased drawing. For many of the resulting optimization
problems, we either find polynomial time algorithms or NP-hardness results.
