In a Knight's Tour, the knight travels on each square only once. The number of possible tours is vast, with trillions of distinct closed tours (where the final square is a knight's move from the start) on a standard 8x8 chessboard. The exact number of open tours (where the end square doesn't connect to the start) is unknown.

This is only one example of the many processes involved linked to the Large Parchment.

In the “decipherment” of the Large Parchment, only its creator knows the “code” (so-called) on how to convert the inscription on the gravestone of Marie de Nègre d'Ables to the “Shepherdess, No Temptation” message; and vice-versa. It is not really a “decipherment”. It's another Philippe de Chérisey confidence trick.