Actually I haven't quite figured out that one myself! Several people have tried to explain it. Check out the following links.

Seabright
Connie Walters
Roy Dommett
King's Morris
Greenwood Morris
Wyre Forest
St. Albans Morris Men
Pigsty Morris
Albermarle Morris Men
Red Herring

The above is just a random selection of pages found using a search engine. If you find any better descriptions out there is cyberspace please let me know.