Consideration of homonymy does not extend to the names of taxa not treated as algae, fungi, or plants, except as stated below:
Later homonyms of the names of taxa once treated as algae, fungi, or plants are illegitimate, even when the taxa have been reassigned to a different group of organisms to which this Code does not apply.
A name originally published for a taxon other than an alga, fungus, or plant, even if validly published under this Code (Art. 32–45), is illegitimate if it becomes a homonym of an algal, fungal, or plant name when the taxon to which it applies is first treated as an alga, fungus, or plant (see also Art. 45.1).
The International Code of Nomenclature of Bacteria provides that a bacterial name is illegitimate if it is a later homonym of a name of a taxon of bacteria, fungi, algae, protozoa, or viruses.
Authors naming new taxa under this Code should, as far as is practicable, avoid using such names as already exist for zoological and bacteriological taxa.