In the phenomenon of
Engineering education, a single 8.5 by 11 inch sheet of paper permitted into an examination. It is not
cheating, per se.
I don't share the resentment
Zorin has for information he no longer actively uses. My perception is very different: Properly done, a cheat sheet is a work of
art, describing the maximum-ever state of your knowledge of a topic. Indeed, the act of producing a cheat sheet involves distilling one's knowledge into as concentrated a form as possible, after which the cheat sheet is not strictly necessary. I spent many hours on my cheat sheets and kept every one. Some would prove useful in later life, while most could be safely forgotten.
Memory Lane:
Henry's Law, as described on my CIVL 480 "
Subsurface Contamination by Hazardous Industrial Liquids" course cheat sheet:
P
i = H * C
i