bread crumbs

n. 1. Debugging statements inserted into a program that emit output or log
indicators of the program's state to a file so you can see where it dies or
pin down the cause of surprising behavior. The term is probably a reference
to the Hansel and Gretel story from the Brothers Grimm or the older French
folktale of Thumbelina; in several variants of these, a character leaves a
trail of bread crumbs so as not to get lost in the woods. 2. In
user-interface design, any feature that allows some tracking of where you've
been, like coloring visited links purple rather than blue in Netscape (also
called footprinting ).

