def self.disjoint_taxon_name_relationships
    self.parent.disjoint_taxon_name_relationships +
      self.collect_to_s(TaxonNameRelationship::Icn::Unaccepting::Synonym::Homotypic,
                        TaxonNameRelationship::Icn::Unaccepting::Synonym::Homotypic::Isonym,
                        TaxonNameRelationship::Icn::Unaccepting::Synonym::Homotypic::OrthographicVariant,