Table 1 List of the debated articles, examples, notes and recommendations of the International Code of Nomenclature for algae, fungi, and plants (ICNafp 2017, Shenzhen Code; Turland et al. 2018), with selected key points to note in bold

Art. 8.4. Type specimens of names of taxa must be preserved permanently and may not be living organisms or cultures. Nevertheless, cultures of algae and fungi, if preserved in a metabolically inactive state (e.g. by lyophilization or deep-freezing to remain alive in that inactive state), are acceptable as types (see also Art. 40.8).

Ex. 11. “Dendrobium sibuyanense” (Lubag-Arquiza & al. in Philipp. Agric. Sci. 88: 484–488. 2005) was described with the statement “Type specimen is a living specimen being maintained at the Orchid Nursery, Department of Horticulture, University of the Philippines Los Baños (UPLB). Collectors: Orville C. Baldos & Ramil R. Marasigan, April 5, 2004”. However, this is a living collection and, as such, is not acceptable as a type. Consequently no type was indicated and the name was not validly published (Art. 40.1).

Ex. 12. The strain CBS 7351 is acceptable as the type of the name Candida populi Hagler & al. (in Int. J. Syst. Bacteriol. 39: 98. 1989) because it is permanently preserved in a metabolically inactive state by lyophilization (see also Rec. 8B.2).

Rec. 8B.2. In cases where the type of a name is a culture permanently preserved in a metabolically inactive state (see Art. 8.4), any living isolates obtained from it should be referred to as “ex-type” (ex typo), “ex-holotype” (ex holotypo), “ex-isotype” (ex isotypo), etc., in order to make it clear they are derived from the type but are not themselves the nomenclatural type.

Art. 9.2. If a designation of holotype made in the protologue of the name of a taxon is later found to contain errors (e.g. in locality, date, collector, collecting number, herbarium code, specimen identifier, or citation of an illustration), these errors are to be corrected provided that the intent of the original author(s) is not changed. However, omissions of required information under Art. 40.6–40.8 are not correctable.

Rec. 9B.1. In selecting a neotype, particular care and critical knowledge should be exercised because there is usually no guide except personal judgement as to what best fits the protologue; if this selection proves to be faulty it may result in further change.

Art. 40.6. For the name of a new taxon at the rank of genus or below published on or after 1 January 1990, indication of the type must include one of the words “typus” or “holotypus”, or its abbreviation, or its equivalent in a modern language (see also Rec. 40A.1 and 40A.4). But in the case of the name of a monotypic (as defined in Art. 38.6) new genus or subdivision of a genus with the simultaneously published name of a new species, indication of the type of the species name is sufficient.

Ex. 7. When Stephenson described “Sedum mucizonia (Ortega) Raym.-Hamet subsp. urceolatum” (in Cact. Succ. J. (Los Angeles) 64: 234. 1992) the name was not validly published because the protologue lacked the indication “typus” or “holotypus”, or its abbreviation, or its equivalent in a modern language, a requirement for names published on or after 1 January 1990.

Art. 40.7. For the name of a new species or infraspecific taxon published on or after 1 January 1990 of which the type is a specimen or unpublished illustration, the single herbarium, collection, or institution in which the type is conserved must be specified (see also Rec. 40A.5 and 40A.6).

Ex. 8. In the protologue of Setaria excurrens var. leviflora Keng ex S. L. Chen (in Bull. Nanjing Bot. Gard. 1988–1989: 3. 1990) the gathering Guangxi Team 4088 was indicated as “模式” [type] and the herbarium where the type is conserved was specified as “中国科学院植物研究所标本室” [Herbarium, Institute of Botany, The Chinese Academy of Sciences], i.e. PE.

Note 4. Specification of the herbarium, collection, or institution may be made in an abbreviated form, e.g. as given in Index Herbariorum (http://sweetgum.nybg.org/science/ih/) or in the World directory of collections of cultures of microorganisms ^a.

Ex. 9. When ‘t Hart described “Sedum eriocarpum subsp. spathulifolium” (in Ot Sist. Bot. Dergisi 2 (2): 7. 1995) the name was not validly published because no herbarium, collection, or institution in which the holotype specimen was conserved was specified. Valid publication was effected when ‘t Hart (in Strid & Tan, Fl. Hellen. 2: 325. 2002) wrote “Type … ‘t Hart HRT-27104 … (U)” while providing a full and direct reference to his previously published Latin diagnosis (Art. 33.1).

Art. 40.8. For the name of a new species or infraspecific taxon published on or after 1 January 2019 of which the type is a culture, the protologue must include a statement that the culture is preserved in a metabolically inactive state.