The Code recognises three groups of names, according to rank:
Within each group, the same authorship applies regardless of the taxon level to which the name (with, in the case of a family-group name, the appropriate ending) is applied. For example, the taxa that the red admiral butterfly can be assigned to:
The identity of the author had long been a matter of dispute and of secondary importance. In the first attempt to provide international rules for zoological nomenclature in 1895, the author was defined as the author of the scientific description, and not as the person who provided the name (published or unpublished), as had been usual practice in various animal groups before. This had the result that in some disciplines, for example in malacology, most taxonomic names had to change their authorship because they had been attributed to other persons who never published a scientific work.
This new rule was however not sufficiently accurate and did not provide an exact guide, so that in the following decades taxonomic practice continued to diverge among disciplines and authors. The ambiguous situation led a member of the ICZN Commission in 1974 to provide an interpretation of Art. 50 of the second edition of the Code (effective since 1961), where the author had been defined as "the person who first publishes a scientific name in a way that satisfies the criteria of availability", an interpretation following which this should be seen as largely being restricted to providing a description or diagnosis.
Currently most (but not all) taxonomists accept this view and restrict authorship for a taxonomic name to the person who was responsible for having written the textual scientific content of the original description, or in other words, the visibly responsible person for having written down what the publisher finally published. The author of an image is not recognized as co-author of a name, even if the image was the only base provided for making the name available.