1. noun
a) A very short abbreviation, often with little correlation to the item it represents
You assigned the same "unique" code to two intake-categories, causing a database error!
b) A body of law, sanctioned by legislation, in which the rules of law to be specifically applied by the courts are set forth in systematic form; a compilation of laws by public authority; a digest.
"The collection of laws made by the order of Justinian is sometimes called, by way of eminence, "The Code"." -Wharton
2. verb
a) To write software programs.
We should code the messages we sent out on usenet.
b) To categorise by assigning identifiers from a schedule, for example CPT coding for medical insurance purposes.
Wikipedia foundation.