licenses of guides

We had a small discussion about guides license on http://www.hikingforums.net/. It's about whether hiking guides are with general license. I was wondering if hiking guides had general global-standard license, or regional license as tour guides.

Thanks to natchez's reply - "It would seem that a hiking guide of a specific area would only need to have thorough knowledge of the area he is employed in as a hiking guide, but on the other hand it doesn't make sense either.... "

My general impression has it that a tour guide relates to culture while hiking guides to nature. Culture is diversed but nature has something in common. E.g. A tour guide of New York is probably unable to guide in Beijing. But hiking in Chiangmai mountains might be similar with that in Shangri-la. Same about fishing guides, diving guides etc. etc.

There are currently heat discussions about "Tour guides sue over history test requirement" (Associated Press, updated 8:33 p.m. ET July 2, 2008)-
"PHILADELPHIA - Citing their free speech rights, three tour guides filed a lawsuit Wednesday challenging an ordinance that will require them to pass a history test and get a license before speaking to groups about the history of the Liberty Bell, Independence Hall and other landmarks..."

Whichever licenses, they show only that one passed some exams and had certain knowledge. What really makes a good guide is his real skill and the client's feedback after the guided tour.