URN -> concept

URN urn:opendata:concept
Description Concept. Object id = sha-1 hash from the concept name. For example, "libertarian" has the id "6ee529f11612b7b08a26898dc5a1df16df89326c"
Example urn:opendata:concept:6ee529f11612b7b08a26898dc5a1df16df89326c