A Cipher of Henry of Navarre before Accession to the French Throne (1587)

I uploaded a new article "A Cipher of Henry of Navarre before Accession to the French Throne (1587)", which presents a cipher used in a letter of Henry of Navarre to Buzenval. This is the only cipher I know of Henry IV before his accession to the French throne. Interestingly, it is a figure cipher, consisting of two- or three-digit figures. In France, such a figure cipher was not yet common at the time, though there were other sporadic examples as I wrote in the last post.