Manicule
Cicero (Quintus Tullius Cicero), Paradoxica storicorum  
[Micellaneous littera, historia et scientifica] 
Italy 13?? –14??  Paper manuscript Ms UCB 085 f.5v
Bancroft Library University of California, Berkeley 

Manicules, or pointing fingers, are marks that readers used to alert them to reconsider or remember—medieval “highlighter”. Students were encouraged to write in their books. Many scribes and readers embellished and doodled for pleasure or distraction. Readers’ marks are as unique as handwriting.