1. A dictionary comprising codevectors of variable dimension and intended to be used in a device for compression coding and/or decoding of digital signals, by vector quantization at variable rate defining a variable resolution, wherein on the one hand, for a given dimension, inter-embedded dictionaries of increasing resolution, and, on the other hand, for a given dimension, a union: of a first set consisting of codevectors constructed by inserting, into codevectors of dictionaries of lower dimension, elements taken from a finite set of real numbers according to a finite collection of predetermined insertion rules, and of a second set consisting of codevectors that may not be obtained by insertion into codevectors of lower dimension of the elements of said finite set according to said collection of insertion rules.