A comma separated list of scientific taxon names that indicate (for administrative and data discovery purposes only) the taxonomic placement of this object. The value may be a single word such as 'Ericaceae' or a series of comma separated words such as "Magnoliopsida, Ericales, Ericaceae, Arbutus". The words should represent taxa of decreasing rank. This property should not be used in place of a formal taxonomic hierarchy constructed using TaxonConcept objects.