Nomen Nudum - in Zoology

In Zoology

According to the rules of zoological nomenclature a nomen nudum is unavailable; the glossary of the International Code of Zoological Nomenclature gives this definition:

nomen nudum (pl. nomina nuda), n.
A Latin term referring to a name that, if published before 1931, fails to conform to Article 12; or, if published after 1930, fails to conform to Article 13.

And among the rules of that same Zoological Code:

12.1. To be available, every new name published before 1931 must … be accompanied by a description or a definition of the taxon that it denotes, or by an indication . …
13.1. To be available, every new name published after 1930 must … be accompanied by a description or definition that states in words characters that are purported to differentiate the taxon, or be accompanied by a bibliographic reference to such a published statement.