XSLT/XPath Reference: XSLT elements, EXSLT functions, XPath functions, XPath axes set:distinct() returns a subset of the nodes in the specified node-set, returning only nodes with unique string values. Syntax set:distinct(nodeSet) Arguments nodeSet The node-set in which to find unique nodes. Returns A node-set containing the nodes that have unique string values. Defined EXSLT - SET:DISTINCT Gecko support Supported in Gecko 1.9 and later.