In European editions, the code on the cover reads "Think fairy, think again" the slogan for the original Artemis Fowl. The code is not written in Gnommish or Centaurian, instead supposedly written in the "eternity code" with which the C Cube is encrypted.
In the hardcover edition, the code for Eoin Colfer Artemis Fowl The Eternity Code Puffin is printed on the spine underneath the dustjacket, allowing the reader to decipher the code inside the book, which is a message from Artemis asking the reader to help him regain his memories by spreading the message that Artemis Fowl must find Mulch Diggums[2]
In the reprint of the book, the Eternity Code is changed to Gnommish.
