APOSTOLICAL BRIEFS, letters which the pope despatches to princes or other magistrates, relating to any public affair. A brief is distinguished from a bull in being more concise, written usually on paper, sealed with red wax, and impressed with the seal of the fisherman, or St Peter in a boat. A bull is more ample, is written on parchment, and sealed with lead or green wax. (Ciampini, Dissertatio de Abbrev. Munere, cap. iii.)