<http://schema.org/description>
"Before people go out on a hiking or climbing expedition, they typically prefer to know what&amp;#039;s in store for them. How difficult will a climb be? Will it be relatively easy, or are there many obstacles along the way? Climbing grades attempt to answer these questions."^^<http://www.w3.org/2001/XMLSchema#string>
<http://adventure.howstuffworks.com/outdoor-activities/climbing/calculate-climbing-grade3.htm>