Permutation Encoding for Text Steganography: A Short Tutorial

We explore a method of encoding secret messages using factoradic numbering of permuted lists of text or numeric elements. Encoding and decoding methods are provided, with code, and key aspects of the correctness of the methods are formally proven. The method of encoding is simple and provides a working example of using textual and numeric lists as a stenagographic channel. Given the ubiquity of lists, such channels are already present but are often unused.