.HEAD 0 +  ThinkTank
.HEAD 1 +  Early Outliner
.HEAD 2 -  Created by Dave Winer
Who also created the OPML format
.HEAD 2 -  http://www.outliners.com/thinkTank2Pc
.HEAD 1 +  Simple text format
.HEAD 2 -  Each heading line begins with '.HEAD n s  text'
Where n is a number representing the level of the heading
s is either + or -, depending on whether the heading has subheadings or not
text is the text
.HEAD 2 -  A normal text line is just that - normal text, after a heading
.HEAD 2 -  A deleted line begins with '^Z'
