Copiale cipher

Copiale cipher is an encrypted manuscript consisting of 75,000 handwritten characters filling 105 pages in a bound volume, found in an archive in former East Germany, at the Akademie der Künste. It includes abstract symbols, as well as letters from Greek and most of the Roman alphabet. The only plain text in the book is "Copiales 3" at the end and "Philipp 1866" on the flyleaf. Philipp is thought to have been an owner of the manuscript. It is thought to date to between 1760 and 1780.
In 2011, it was decoded using modern computer techniques by Kevin Knight of the University of Southern California, along with Beáta Megyesi and Christiane Schaefer of Uppsala University in Sweden. They found it to be a complex substitution code.
Treating almost all the Roman letters as standing for spaces, and transcribing and decoding only the abstract symbols, they found that the initial portion of 16 pages describes an initiation ceremony for an unidentified secret society related to Freemasonry. The document describes an initiation ritual in which the candidate is asked to read a blank piece of paper, and on confessing inability to do so, is given eyeglasses and asked to try again, and then again after washing the eyes with a cloth, followed by an "operation" in which a single eyebrow hair is plucked. The secret organization predates noted occult groups such as the Hermetic Order of the Golden Dawn.