XOXO
From Just Solve the File Format Problem
XOXO (Extensible Open XHTML Outlines) is one of several "microformats" released via the microformats.org site and community, intended for the representation of information in a manner that is human-readable but can still be processed by machines.
The format specifies data giving an outline of a document, concept, etc., in the form of XHTML of a standardized form which can be automatically processed while remaining usable as part of a HTML/XML document.
