[Competition] Best folio number parallels.

[Koen G]

The opinions on the dating of the folio numbers are not entirely consistent. I found these using Ed's search tool:

• D'Imperio: "Some students have dated the folio numbers to the sixteenth or seventeenth century; they may well have been added by someone at Rudolph's court. The forms of the numbers do not differ significantly from modern forms."
  
• Voynich.nu: "The folio numbers appear in a style that is less constrained in time. De Ricci (1937) gives the 16th Century and Manly (1931) the 17th (based on the handwriting style). A 15th century date may also not be excluded."
  
• Lisa Fagin Davis maintains that the folio numbers were added in the 17th century, based on their style. You are not allowed to view links. Register or Login to view.
  

Estimates are increasingly restrictive. Rene gives 15th-17th, D'imperio 16th-17th, LFD just 17th. I have not found any source that actually tells us which features they are looking at.