The derivation of the word hoax, like the concept it describes, is slippery. The OED suggests a possible contraction of the magical ‘hocus pocus’, itself a corruption of the ‘hoc est corpus’ of the Latin mass, although this can’t be pinned down. Transubstantiation is certainly a useful idea for considering the hoax, a deception that emphasises the blurred boundaries between metaphor, fact and fiction, accident and intent, author, narrator and subject, and, on occasion, words and things.
Literary hoaxes run the gamut of grey areas from misread satires, outright frauds, misappropriated material and works yet more mysterious: crypto-texts such as the Voynich manuscript, whose status remain undecided, may yet turn out to be hoaxes. Contested identity is more often than not at the heart of the literary hoax.
By Mark Blacklock; more at The Guardian