FontCode isn’t a typeface exactly, it is instead a steganographical method of hiding information in a normal looking text document by subtly altering (or ‘perturbing’) the shapes of the glyphs. This can then be interpreted by software, such as an app on a phone, to reveal the message within the message.
See also
- FontCode by Chang Xiao, Cheng Zhang, Changxi Zheng at Columbia University.
- FontCode: Embedding Information in Text Documents using Glyph
Perturbation [PDF]
(via @daniel_bilar via @bruces)