Opening page of a manuscript of Diceto's historical works, including a table of signs and images used in the text to mark some of the subjects treated in the text, with explanations of their meanings. "The lower half of the left column is occupied by a key to understanding a series of twelve visual indexing symbols, which function rather like computer icons: they are small easily recognised mnemonic symbols, which are placed next to passages of text to give an indication of its content. Thus, a crown represents the anointing of a king, a sword represents the dukes of Normandy, and a crown being grasped by two hands from opposite sides represents the arguments between King Henry II and his three sons." - BL Online Gallery webpage .