What is "gnommish"

Gnommish is the " fairy language" used in the Artemis Fowl series by Eoin Colfer. It is not actually a language at all, but the English language encoded into a letter-substitution cipher where each symbol represents a letter. Lines of translatable Gnommish run along the bottoms of books one, two, four, five and six. However, in book one of the series, it is mentioned that one of the symbols was comparable to the Egyptian Anubis symbol. It is also mentioned that Gnommish is a mix of symbolic and alphabetic letters, running in spirals (but since reading in spirals gives most fairies migraines, most modern fairy script is arranged in horizontal lines).