codebook

plural codebooks

1. computingA book, table, database, or other object that stores the mapping between plaintext words or phrases and their equivalents in a code.

   Here's the codebook! Study it again! You mixed up K and T! One more mistake and you're fired!

   2025, Jason, Death in Trieste, page unpaged

   1 more example

   In the 19th century codebooks were used not so much for secrecy as for compression, to bring down the prohibitive cost of telegraph communication. […] But when Dr. Bellovin hunted though the card catalog, his interest was piqued by an 1882 codebook whose title included the word “secrecy.”

   2011 July 25, John Markoff, “Codebook Shows an Encryption Form Dates Back to Telegraphs”, in The New York Times

2. computerA lookup table.

   We assume that DWT coefficients belong to a codeblock that is divided by its quantization step size in advance and the two codebooks, C⁰ and C¹, for the two quantizers can be defined as […]

   2013, Kazuhiro Kondo, Multimedia Information Hiding Technologies and Methodologies for Controlling Data, Hershey, P.A.: Information Science Reference, →ISBN, page 226, column 2

3. medicineA list of disorders or conditions and the codes that represent them.

   The change, which has so far been approved by each committee that has considered it, is under review for the next edition of the W.H.O. codebook, which classifies diseases and influences the treatment of patients worldwide.

   2016 July 26, Pam Belluck, “W.H.O. Weighs Dropping Transgender Identity From List of Mental Disorders”, in The New York Times