Regarding other living organisms, tautonyms were prohibited in bacteriological nomenclature from 1947 until 1975, but they are now permitted for all bacteria and prokaryotes.
[9] In the current rules for botanical nomenclature (which apply retroactively), tautonyms are explicitly prohibited.
However, it is allowed for both parts of the name of a species to mean the same (pleonasm), without being identical in spelling.
Instances that repeat the genus name with a slight modification, such as Lycopersicon lycopersicum (Greek and Latinized Greek, a rejected name for the tomato) and Ziziphus zizyphus, have been contentious, but are in accord with the Code of Nomenclature.
[12] In April 2023, a proposal was made to permit tautonyms in botanical nomenclature on a non-retroactive basis, noting that tautonyms have been allowed in zoological and bacteriological codes for decades without incident, and that allowing tautonyms would simplify botany's nomenclatural code while eliminating certain naming problems and preserving the epithets originally assigned to species.