Backwards alphabet

Also known as a "retrograde alphabet," it is a relativelys simple cipher that is used for encoding messages. The latter "A" becomes "Z", "Y" turns into "B," "X" is "C," and so on. The number "0" becomes "9," "1" turns into "8," etc. Because of its very simplicity, the backwards alphabet can occassionally be quite effective in situations where a complex code is expected.