The most valuable work published by the Royal Spanish Academy (RAE) is its first dictionary, usually called the Diccionario de autoridades (DA1 1726-1739). The institution was created, first of all, for this highly important lexicographical feat. The Diccionario Vulgar, until recently known as de la Real Academia Española (DRAE), and currently as de la lengua española (DLE), is a reduction of the 6 volumes of the Diccionario de Autoridades into one single volume, following suppression of the authorities, that is, the texts that authorize use of a specific word. While the academics were finalizing the edition of the fifth volume, which was published in 1737, they were already thinking about revising the complete lexicographical work. The purpose was to finish the dictionary, so the frantic pace of work did not slow down, although the work was almost at its end. Starting from 1737, it was decided to work simultaneously on the last volume of the DA1 (1726-1739) and on an in-depth revision of the work, which initially should have been a six-volume supplement, but in the end turned into a second edition. This came about thanks to the corrections and the increase in new entries, using the traditional method of distributing the different combinations of letters (p. [xiv]) among the members of the Docta Casa. We can imagine that the work was rather like polishing a rough diamond in order to increase its value. But, of course, this could be achieved only if the work were completed.