Copyright (c) 2007 Anoto AB and its licensors. All rights reserved.

The filename convention is as follows
-------------------------------------

(dotalgorithm name)_single_[header|tail].inc is for -d1
(dotalgorithm name)_multi_[header|tail].inc is for -d2 and -d3
(dotalgorithm name)_duo_[header|tail].inc is for -pbw (black and white color separation)

header is first part of dotalgorithm definition up to the by GAPAT defined XUID of the font
tail is the rest

different file sets are trigged by setting the environment variable --dotinclude. 
If no --dotinclude is set treat it as if dotinclude=default 

example: --dotalgorithm myAlgo will use

myAlgo_single.inc if default -d1 is used

Note that its very tricky to write a proper _multi algorithm.

Basics of the encoding for _multi (d2/d3) is:

Each single dot can be coded as one letter
Each 2 dot combination can be coded as one letter
Each 3 dot combination can be coded as one letter
"Space" can be coded in binary intervals i.e. base glyps is a=" ", b="  ", c="    ", d="        "
i.e. "   " can be coded as (ab)
and dont forget about the null pattern

difference between 2 and 3 dot algorithm is only the USE of the glyphs. The definition file is the same

This is the documentation there is.