- Names of nothotaxa at the rank of species or below must conform with the provisions (a) in the body of the Code applicable to names in the same ranks (see Art. 32.4) and (b) in Art. H.3. Infringements of Art. H.3.1 are treated as errors to be corrected (see also Art. 11.9).
- The nothospecific name Melampsora ×columbiana G. Newc. (in Mycol. Res. 104: 271. 2000) was validly published, with a Latin description and designation of a holotype, for the hybrid between M. medusae Thüm. and M. occidentalis H. S. Jacks.
- The following are considered to be formulae and not true epithets: designations consisting of the epithets of the names of the parents combined in unaltered form by a hyphen, or with only the termination of one epithet changed, or consisting of the specific epithet of the name of one parent combined with the generic name of the other (with or without change of termination).
- The designation Potentilla “atrosanguinea-pedata” published by Maund (in Bot. Gard. 5: No. 385, t. 97. 1833) is considered to be a formula meaning P. atrosanguinea Lodd. ex D. Don × P. pedata Nestl.
- Verbascum “nigro-lychnitis” (Schiede, Pl. Hybr.: 40. 1825) is considered to be a formula, V. lychnitis L. × V. nigrum L.; the correct binary name for this hybrid is V. ×schiedeanum W. D. J. Koch (1844).
- In Acaena ×anserovina Orchard (1969) (A. anserinifolia (J. R. Forst. & G. Forst.) J. Armstr. × A. ovina A. Cunn.) the epithet (contrary to Rec. H.10A) combines the first part of the first and the whole of the second epithet in the names of the parental species; as more than the termination of the first epithet is omitted, anserovina is a true epithet.
- In Micromeria ×benthamineolens Svent. (1969) (M. benthamii Webb & Berthel. × M. pineolens Svent.) the epithet (contrary to Rec. H.10A) combines the first part of the first and the second part of the second epithet in the names of the parental species; as neither epithet is unaltered, benthamineolens is a true epithet.
- Since the name of a nothotaxon at the rank of species or below has a type, statements of parentage play a secondary part in determining the application of the name.
- Quercus ×deamii Trel. (in Mem. Natl. Acad. Sci. 20: 14. 1924) when described was considered as the cross Q. alba L. × Q. muehlenbergii Engelm. However, progeny grown from acorns of the tree from which the type originated led Bartlett to conclude that the parents were in fact Q. macrocarpa Michx. and Q. muehlenbergii. If this conclusion is accepted, the name Q. ×deamii applies to Q. macrocarpa × Q. muehlenbergii, and not to Q. alba × Q. muehlenbergii.
- In forming epithets for names of nothotaxa at the rank of species and below, authors should avoid combining parts of the epithets of the names of the parents.