Rule 27 of the International Code of Nomenclature of prokaryotes: the basonym is not enough.

Proposals to make changes to the wording of Rule 27 of the International Code of Nomenclature of Prokaryotes have been made that include the requirement to make reference to the basonym of a new combination. While this is a step in the right direction, it does not solve problems where new combinations are associated with multiple heterotypic synonyms and the new combination is based on the selection of the genus name or species epithet that is contrary to the Rules.