For example, output the rows of a value set in XML format:
SELECT XMLElement("GL_NOMINAL" ,XMLForest(ffv.flex_value AS "VALUE" ,ffv.description AS "DESC" ) ) FROM fnd_flex_values_vl ffv , fnd_flex_value_sets ffvs WHERE ffv.flex_value_set_id = ffvs.flex_value_set_id AND ffvs.flex_value_set_name = 'GL_NOMINAL' AND ffv.enabled_flag = 'Y' AND ffv.summary_flag = 'N' ORDER BY ffv.flex_value ASC ;