Proposal to modify the Rules of the International Code of Nomenclature of Prokaryotes to abolish the taxonomic categories Subfamily, Subtribe and Kingdom

Although the taxonomic categories covered by the International Code of Nomenclature of Prokaryotes include the ranks of Subtribe (Subtribus) and Subfamily (Subfamilia), no names of taxa belonging to these ranks have been validly published. To simplify the Rules of the Code I propose abolishing these ranks. The rank of Kingdom is mentioned once in the Code, in an example to Rule 8, but it is not further defined. Therefore, I propose modifying that example so that the rank of Kingdom is no longer mentioned in the Code.