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
`footrinting').