isPlural (http://rs.gbif.org/terms/1.0/isPlural) @return [String] This value is true if the vernacular name it qualifies refers to a plural form of the name. Vocabulary: http://rs.gbif.org/vocabulary/basic/boolean.xml Example: The term "Schoolies" is the plural form of a name used along the coastal Northeastern U.S. for groups of juvenile fish of the species, Morone saxatilis.