When people say "Green Guide" they usually are referring to the Michelin Green Guide (which are general guides to a destination as opposed to the Michelin Red Guide which is famous for awarding stars to restaurants and hotels.
There is a Michelin Green Guide, published a few years ago, to Mexico, Guatemala and Belize (the Belize section is only a few pages long).
Green Guide is probably a trademark of Michelin, so if someone else is selling a Green Guide they may hear from Michelin's lawyers.
--Lan Sluder