The recent publication of an alternative nomenclatural code that targets prokaryotes, the Code of Nomenclature of Prokaryotes Described from DNA Sequence Data (SeqCode), raises questions about how to treat names 'validly published' under that code in the International Journal of Systematic and Evolutionary Microbiology (IJSEM). Here, it is reiterated that the IJSEM must function in accordance with the International Code of Nomenclature of Prokaryotes (ICNP). It is also reiterated that the ICNP covers all prokaryotes and that it accordingly assigns a nomenclatural status to all names of prokaryotic taxa. This implies that the ICNP also assigns a status to names that are only 'validly published' under the SeqCode. It follows that the IJSEM must treat such names as not validly published, since 'validly published under the SeqCode' is not a nomenclatural status, under the ICNP. Such names should be marked accordingly as Candidatus names or printed in quotation marks. The same measures would need to be taken by other journals which intend to adhere to the ICNP.
Keywords: DNA sequences; archaea; bacteria; classification; cultivation; nomenclature.