In all languages, humans frequently use linguistic combinations called phraseological units (PUs) in communicative acts. These PUs are characterized by their institutionalized fixation and, in many cases, by their opacity. Traditionally, the work on phraseology has placed the emphasis on the total fixing of components and structures of verbal expressions. Variation in PUs is currently an uncontested fact and has been extensively studied and analyzed. In addition, in the case of languages like Spanish, English, French, spoken in many countries, new creations or diatopic variants arise. While these diatopic expressions have been collected or analyzed in their territory of influence, no comprehensive collection showing all the expressions and contrastive analysis to observe the similarities and differences between these diatopic creations with all their idiosyncratic and cultural references have been made so far. The content of this volume deals with numerous linguistic, lexicographic and translational problems in the context of language variation in general, as well as specifically related to diatopic variation. The aim is to make progress in these challenging and highly interesting areas which still pose many comprehension and translation problems.