"A situation in which a person or organization does not have to pay tax." (CD)
The graph displays the other subjects mentioned on the same pages as the subject "Taxation--Exemption". If the same subject occurs on a page with "Taxation--Exemption" more than once, it appears closer to "Taxation--Exemption" on the graph, and is colored in a darker shade. The closer a subject is to the center, the more "related" the subjects are.