As with previous novels, at least beginning with The Da Vinci Code, the dustcover of the United States edition has contained concealed messages. The hunt to find such symbols began with the original graphic of the cover posted to Facebook, but it may have contained a misprint (perhaps intentional).
In addition to the portrait of Dante and view of Florence, there is a series of nine rings with the Roman numerals, mirroring Dante’s nine circles of hell. There are also inside the rings ten letters c-a-t-r-o-v-a-c-e-r. Those who have read the novel will decipher these into Cerca trova. But there is more. There are seven words in Latin, some partially obscured that correspond to the Seven Deadly Sins: superbia, avaritia, luxuria, invidia, gula, ira, acedia.
On the spine in faint lettering is VI 74 75. In the Mandelbaum translation, the one Langdon and likely Brown rely upon, Canto Six lines 74 and 75 of Inferno are translated as:
“Three sparks that set on fire every heart are envy, pride, and avariciousness.”
On the back cover in the lower right hand corner is H+, a symbol of Transhumanism. There is also an indistinct set of letters and numbers on the upper right of the back cover. DB 2064. Dan Brown was born in 1964. His initials D. B. along with his age at 100 (2064) would be his Transhumanist code name. (Thanks to Gordon Nickerson for this revelation).
On the inside of the dustcover front and back, similar to the technique used in The Da Vinci Code, there are a few letters printed in BOLD typeface. The letters spell out s-a-l-i-g-i-a, the mnemonic for the Seven Deadly Sins referenced above.
In his kickoff event at Lincoln Center on May 15, 2013, Brown mentioned in passing that the release date of the novel, 5.14.13, was in fact the numerical value of PI written in reverse, 3.1415. He also noted that the intricate cover art and its messages were merely for the amusement of his editors and him.
Unless and until other secrets are revealed, this novel’s dustcover differs from earlier ones in that it refers only to the novel at hand, instead of a future one.