I've looked around for precise definitions, but couldn't find any. But the jellyfish match format (*.mat) is very human readable, and could be learned by example. On http://www.nbgf.no/matches/ we have some matches in mat format. If anything is unclear, the matches are also available in html format with board images. If you need more, I'll send you some. If there is any situations unaccounted for, I'll send you some with those situations. gnubg is good for testing. And also for playing matches and exporting them in mat format for more examples.