 Usually the heading of the title and sometimes the first words of the chapter are quoted; for instance, "c. 3, X, III, 23", or "c. Odoardus, X, De solutionibus, HI, 23", refers to the third chapter, commencing with the word Odoardus, in the Decretals of Gregory IX, book III, title 23, which is entitled "De solutionibus".If the number of the chapter or of the title is not indicated it will easily be learned on consulting the alphabetical indexes of the rubrics and of the introductory words of the chapters, which are to be found in all editions of the "Corpus Juris Canonici".Gregory IX sent this new collection to the Universities of Bologna and Paris, and declared, by the Bull "Rex pacificus" of 5 September 1234, that this compilation was the official code of the canon law.