Dear category theorists, From time to time in this list appear discussions about : who must be credited for a result or the introduction of a new notion. Although I have been quite "surprised" by some of the answers, I have so far refrained from participating in such discussions, especially because I was often directly concerned. I break this "personal rule" because of the answer given by Claudio Harmida to Agusti Roig about 2-fibrations. For these, he refers to two papers of his, the fist one published in 1999, the second presented in september 2002 and still in print. The notions of 2-fibration, and 2-stack, are MUCH MUCH OLDER. They appear, and are used in the following BOOK: Topos anneles et schemas relatifs, by Monique Hakim in 1972 (Volume 64 of the "Ergebnisse der Matemematik" of Springer) I would like to stress the fact that the book is easily available and in english (which seem to be almost necessary, but far from sufficient, conditions to get some recognition). If we drop the conditions of availability and english, the previous notions were introduced, and used, as early as 1967, in Hakim's thesis (Faculte des sciences d'Orsay), unpublished but widely known at least in France, since at the time Hakim was a student of Grothendieck, who was the adviser and gave her many ideas for her work. I apologize both for my english, and for going back to prehistory to find origins.