Codebook

A codebook is a type of document used for gathering and storing cryptography codes.

A codebook contains a lookup table for coding and decoding; each word or phrase has one or more strings which replace it.

The distribution and physical security of codebooks presents a special difficulty in the use of codes compared to the secret information used in ciphers, the key, which is typically much shorter.

In social sciences, a codebook is a document containing a list of the codes used in a set of data to refer to variables and their values, for example locations, occupations, or clinical diagnoses.

The usage is standardized by 3GPP, for example in the document TS 38.331, NR; Radio Resource Control (RRC); Protocol specification.

U.S. State Department code book issued in 1899, an example of a one-part code, at the National Cryptologic Museum
Page 187 of the State Department 1899 code book, a one-part code with a choice of code word or numeric ciphertext. Numeric codes are prefixed by the page number.