Laudator Temporis Acti

Michael Parenti, The Assassination of Julius Caesar: A People's History of Ancient Rome (New York: The New Press, 2003), pp. 223-224:

My desire has been to make the classical sources used herein accessible to the lay reader. Most present-day historians of antiquity seem determined to make them inaccessible, a fact that itself might be indicative of the pedantic and elitist nature of their training. In regard to ancient sources, they resort to a mode of Latin citation so severely abbreviated as to be identifiable only to select colleagues specially schooled in classical literature. So we encounter indecipherable references like "B.i.146" and "De fin., V.65." To add to the difficulty, a key to such arcane abbreviations is rarely provided, thus ensuring that the interested layperson who wishes to delve into ancient sources, or at least fathom what they might be, is properly stymied.

Furthermore, the classicists make a point of not listing the ancient sources in their otherwise copious bibliographies, not even in the original Latin. With the help of lexicons and after a deep immersion in the literature, the persevering lay reader (including the non-classicist historian) eventually might be able to divine that "Sall. Bell Iug 71" is a reference to Sallust Bellum Iugurthinum and is available in English as Sallust's The Jugurthine War. Persistent lay readers might even be able to discover, as I did, that "Plin. NH VII. 91–2" is a reference not to the younger Pliny but to Gaius Secundus Plinius (maior), Naturalis Historia, that is, the elder Pliny's Natural History. But what are the unanointed to do with "Ad Q. fr. II.iv.1" or "Q.F.I.i"? (Which happen to be Ad Quintum Fratrem or To [Cicero's] Brother Quintus.) Knowing enough Latin to guess that "Ep. ad Caes" (or sometimes it is just "ad Caes") is Epistulae ad Caesarem, one can conclude that someone had written a letter to Caesar; but when not even an abbreviation of the author's name is given, we would have to know enough on our own to guess that it was Sallust and not the more likely Cicero whose letters survive in such abundance.

This abstruse mode of citation is used even by progressive scholars such as Neal Wood and the incomparable G.E.M. de Ste. Croix, both of whom otherwise seem interested in communicating with audiences beyond the antiquarian priesthood. One of the few exceptions to such pedantry is Arthur D. Kahn, who in his The Education of Julius Caesar (1986) provides a listing of the ancient sources he used, both in English and Latin, as well as a key to their abbreviations—which is only one of several reasons for welcoming his book.

Most classical scholars (I think) use the abbreviations listed in the Oxford Classical Dictionary.