Codebook

Don't let this codebook fall into enemy hands.

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.”

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

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 […]

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.