Clarifying the limitations on Rule 18a and Rule 30 of the International Code of Nomenclature of Prokaryotes Tindall, B. J.,, 67, 505-506 (2017), doi = https://doi.org/10.1099/ijsem.0.001576, publicationName = Microbiology Society, issn = 1466-5026, abstract= The retroactive changes to Rule 18a proposed at the International (IUMS) Congress of Bacteriology and Applied Microbiology meetings of the Judicial Commission in Jerusalem, 1996, have led to several changes in wording that seek to limit the retroactive effects. However, there remains an ambiguity in the wording that changes may easily correct. Changes to Rule 30 should also be made., language=, type=