Guidelines for interpreting the international code of nomenclature of prokaryotes and for preparing a request for an opinion

1 Guidelines for interpreting the International Code of Nomenclature of Prokaryotes and for preparing a Request for anOpinion David R.Arahal1, Carolee T.Bull2, Hans- JürgenBusse3, HenrikChristensen4, MariaChuvochina5, Svetlana N.Dedysh6, Pierre- EdouardFournier7, Konstantinos T.Konstantinidis8, Charles T.Parker9, RamonRossello- Mora10, AntonioVentosa11 and MarkusGöker12,* ICSP MATTERS Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 DOI 10.1099/ijsem.0.005782 Author affiliations: 1Departamento de Microbiología y Ecología, Universitat de València, Valencia, Spain; 2Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, 211 Buckhout Lab, University Park, PA 16802, USA; 3Institut für Mikrobiologie, University of Veterinary Medicine, Veterinärplatz 1, A- 1210 Wien, Austria; 4Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, 1870 Frederiksberg C, Denmark; 5The University of Queensland, School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics, QLD 4072, Australia; 6Winogradsky Institute of Microbiology, Research Center of Biotechnology RAS, Prospect 60- letya Octyabrya 7/2, Moscow 117312, Russia; 7UMR VITROME, IHU - Méditerranée Infection, 19- 21 Bd Jean Moulin, 13005 Marseille, France; 8School of Civil & Environmental Engineering and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA; 9Names for Life, LLC, East Lansing, Okemos, Michigan 48805- 0769, USA; 10Department of Animal and Microbial Biodiversity, Institut Mediterrani d’Estudis Avançats, CSICUIB, C/Miquel Marqués 21, 07190 Esporles, Illes Balears, Spain; 11Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, ES- 41012 Sevilla, C/. Prof. Garcia Gonzalez 2, Spain; 12Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Inhoffenstrasse 7B, D- 38124 Braunschweig, Germany. *Correspondence: Markus Göker, markus. goeker@ dsmz. de Keywords: advice; archaea; bacteria; classification; manual; regulations; standards. 005782 © 2023 The Authors This is an openaccess article distributed under the terms of the Creative Commons Attribution License. This article was made open access via a Publish and Read agreement between the Microbiology Society and the corresponding author’s institution. Abstract In this paper the Judicial Commission provides general guidance for interpreting the International Code of Nomenclature of Prokaryotes (ICNP) and specific assistance to authors, reviewers and editors of a Request for an Opinion, or of other suggestions related to the ICNP. The role of the Judicial Commission is recapitulated, particularly with respect to the processing of such Requests. Selected kinds of nomenclaturerelated proposals are discussed that are unsuitable as the basis for a Request. Particular emphasis is put on Requests for placing names or epithets on the list of nomina rejicienda, and a dichotomous identification key is provided to guide potential authors of a Request that targets the name of a species or subspecies because of issues with its type strain. To this end, the criteria for the valid publication of such names under the ICNP are revisited. Aspects of other kinds of Requests are also addressed. The study is based on a comprehensive review of all Judicial Opinions issued since the publication of the Approved Lists in 1980. One goal of this paper is to assist potential authors in deciding whether their concern should be the subject of a Request, and if so, in composing it with the greatest chance of success. It is also clarified how to obtain additional help regarding nomenclaturerelated issues. INTRODUCTION A Request for an Opinion (henceforth called Request) as well as a subsequent Judicial Opinion have to be issued in the International Journal of Systematic and Evolutionary Microbiology (IJSEM) and deal with the interpretation of the International Code of Nomenclature of Prokaryotes (ICNP) [1] with respect to specific nomenclaturerelated issues. One of the tasks of the Judicial Commission of the International Committee of Systematics of Prokaryotes (ICSP) is to interpret each Request with reference to the ICNP and to author corresponding Judicial Opinions [2]. Within the ICNP, General Consideration 6(4), Rule 3 and Rule 4 form the basis of actions of the Judicial Commission in general while other Rules provide for specific tasks of Judicial Opinions. The first Opinion dates back to 1951 [3]; Opinions 97–127 were published during the last 3 years [4–11]. Unfortunately, misinterpretations of the ICNP are common and tend to spread [6, 8, 12–22], a process regrettably now amplified by social media. Accordingly, a variety of Requests recently encountered by the Judicial Commission indicated difficulties regarding the interpretation of the ICNP, particularly those that called for the rejection of names or epithets or for a corresponding clarification of the status of a name [23–40]. While other Requests of that kind did not show such misinterpretations [41–43], the large number of avoidable errors in contemporary Requests slows down the work of the Judicial Commission, increases the OPEN ACCESS 2 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 confusion surrounding the ICNP and causes unnecessary disappointments. On the one hand, Requests are necessary for solving a variety of nomenclaturerelated problems. On the other hand, issuing a Request that is unlikely to succeed is also a waste of time for its authors. However, the accurate application of the ICNP is possible. This is confirmed by the observation that some publications already interpret the ICNP more appropriately than others. Hence, it seems likely that additional guidance provided by the Judicial Commission can further the understanding of issues of nomenclature. Appendix 8 of the ICNP [1] is titled ‘Preparation of a Request for an Opinion’ but the text is very brief. Thus, the purpose of this paper is to provide much more detailed assistance to authors, reviewers and editors of a Request and to make other remarks related to the ICNP, including general guidance for interpreting the ICNP, which could be greatly beneficial for writing other types of articles, too. The work is based on a review of all Judicial Opinions issued since the publication of the Approved Lists [44], a thorough crosscomparison with the wording of the ICNP [1], and a compilation of misjudgements related to nomenclature that were encountered by the Judicial Commission in the recent literature. Care was taken to ensure that the conclusions drawn from the Judicial Opinions are not affected by changes between the distinct revisions of the ICNP on which they were based. The 2022 revision of the ICNP was at the time of writing still in press [45]. Again, care was taken to ensure that all conclusions regarding the ICNP equally apply to both revisions, even in the case of quoted passages which deviate between the two revisions. Exceptions are dealt with explicitly as, e.g., in section 7.1. The paper is organized as follows: First, guidelines for reading and understanding a complex document such as the ICNP [1] are provided, and the role of the Judicial Commission and other units within the ICSP is recapitulated in this context, particularly with respect to a Request. The crucial topic of the valid publication of names of species and subspecies under the ICNP is then addressed, with focus on the role of the Judicial Commission and the criteria for the valid publication of such names that are relevant for a Request. This is followed by the discussion of selected kinds of nomenclaturerelated proposals that are unsuitable as a Request. Requests for placing names or epithets on the list of nomina rejicienda are then discussed, and a dichotomous identification key is provided to guide potential authors of a Request that addresses the name of a species or subspecies because of issues with its type strain. Finally, aspects of other kinds of a Request are clarified. 1. INTERPRETING THE ICNP Reading and interpreting nomenclatural texts and especially the regulatory manuscripts such as the ICNP requires practice and different skills than we use to analyse experimental designs and data. Frequently, Requests provide a wealth of wellanalysed empirical information but have not interpreted the ICNP correctly. Interpreting the ICNP [1] may indeed often require the skills of a lawyer rather than the skills of the biologist. However, correctly citing the pertinent literature is an important aspect of proper conduct in science, and whenever the nomenclature of prokaryotes is concerned, the ICNP is obviously of central importance. Below we first reiterate the purpose of the ICNP. To assist in correctly interpreting the ICNP, five major guidelines are then provided, followed by examples which illustrate how failing to adhere to these guidelines may lead to misjudgements about the ICNP. Advice on obtaining help on nomenclaturerelated issues is then given, followed by a brief discussion of potential improvements of the ICNP and their limitations. 1.1 The significance of the ICNP As indicated in Article 7(1)(a) of the statutes of the ICSP [2], the Judicial Commission must make its decisions in the light of the ICNP. The Judicial Commission is thus obliged to apply the ICNP [1]; it does not have a mandate to overrule the ICNP. This holds without exceptions. Rule 3 does mention the possibility to ‘make exceptions to the Rules’, as do General Consideration 6(4) and Appendix 8. However, Rule 3 explicitly refers to Rule 23a. Indeed, Rule 23a Note 4 regulates one type of exception that can be made by the Judicial Commission. These are exceptions from the priority of names, which can be made by placing names on the list of conserved names or on the list of rejected names. Accordingly, the exception that can be made is to overrule one regulation of the ICNP based on another regulation of the ICNP. In an analogous manner, the Note to Rule 30(3)(b) defines exceptions from that Rule. The 2022 revision of the ICNP further defines a possible exception that can be made from Rule 8 [45]. None of these regulated exceptions constitute an actual exception from the need to adhere to the ICNP. For this reason, the major criterion for assessing a Judicial Opinion is not whether its outcome is pleasant but whether the Judicial Commission accurately interpreted the ICNP and the presented facts. Requests that ask for a Judicial Opinion based on the Judicial Commission making an exception to the ICNP are unlikely to be granted. In addition to the Judicial Commission, the other units of the ICSP are also bound to the ICNP when it comes to interpreting issues of nomenclature. As indicated in Article 6(b)(5) of the ICSP statutes [2], the Subcommittees on Taxonomy must work within framework of the ICNP. The same holds for the entire ICSP, which is obvious from Article 3(b) in conjunction with Article 13(b). Thus, the approach to deal with unpleasant consequences of a regulation made by the ICNP is not to overrule that regulation in an ad hoc move, but to propose and vote on an emendation of the ICNP that removes or modifies that regulation. 3 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 Occasionally ‘Supplementary Information’ to a Judicial Opinion was separately published by the Judicial Commission, sometimes going far beyond the topics covered by the original Request [46]. The ICSP statutes do not mention ‘Supplementary Information’ but they do not restrict the scope of a Judicial Opinion other than emphasizing that it must include a response to the Request. Targeting other issues that are obviously related to the issue mentioned in the Request may make sense to immediately fix other known problems. Recent Opinions that additionally targeted issues not mentioned in the underlying Request include Opinions 116, 118 and 120 [7]. Such additions do not undermine the ratification process, nor do they generate dangerous precedents for fixing problems that cannot be known. According to Article 7(a)(1) of the ICSP statutes [2], the crucial issue regarding ‘expert advice’ given by the Judicial Commission is not its respective scope but the need to base it on the ICNP [1]. 1.2 Guidelines for reading the ICNP The ICNP [1] is a complex document organized into prefaces, chapters and appendices. The most pertinent chapter, Chapter 3, is in turn organized into sections, which are subdivided into Rules, to which Notes or Examples may be attached. Recommendations are also included. The last revision of the ICNP [1] is available as electronic document, which facilitates the search for terms. (The next revision of the ICNP [45] will also be available as electronic document.) However, quoting this complex document out of context does occur, as do other misleading usages of the ICNP [4, 5, 7, 9, 12, 14, 15, 17–20]. To minimize the risk of misinterpretations, readers are strongly advised to follow the guidelines given below. (1) Read the entire Rule, including its Notes and Examples, if any. Do not consider only single sentences of the ICNP. Other sentences may define exceptions to the initially considered sentence or may be needed to fully comprehend its meaning. The complete Rule you are referring to is the minimum amount of information to be considered, and if Notes or Examples are given they form an integral part of it. (2) Obtain an overview of the Section you are currently consulting. Look up the title of that Section, and read the Rules within the same Section that are adjacent to the initially considered Rule. Other Rules may complete the Rule you are currently considering, provide exceptions to it, or be necessary to fully elucidate its meaning. Adjacent Rules within the same Section are often closely related to each other. (3) Follow references to other Rules, if any, and also consult those. Rules located in other Sections of the ICNP may be necessary to fully elucidate the meaning of the Rule you are currently considering. Likewise, to fully comprehend the General Considerations and the Principles of the ICNP it is often necessary to study the Rules which implement them. The regulations of the ICNP are often strongly interconnected. (4) Infer the meaning of nomenclatural terms from the ICNP itself. The ICNP may define terms distinctly from their usual meaning in the English language and even from the meaning corresponding to their usage in other scientific publications. The authoritative definition of a term may be given explicitly at another position within the ICNP or only be implicit in the wording of one to several Rules. (5) Strive for a logically consistent interpretation of the ICNP. If distinct interpretations of the wording of a Rule are possible, prefer those that do not logically contradict other statements made in the ICNP. The ICNP is a historically grown document and the wording of some sentences may be misleading, hence several parts of the ICNP may need to be considered for properly inferring the sense of the clause of interest. As shown in section 1.3, not adhering to these Guidelines may well cause a misinterpretation of the ICNP. In section 1.4 we explain how to obtain help and in section 1.5 we discuss potential improvements of the ICNP which could render it more easy to interpret. It must be emphasized, however, that the complexity of a code of nomenclature must reflect the diversity of issues that need to be regulated. Accordingly, one should not prematurely lament the intricacy of documents such as the ICNP [1]. In order to determine the ways, if any, in which the ICNP could actually be simplified, one needs to thoroughly study it in the first place, preferentially by adhering to the Guidelines given here. While every scientist has to deal with complexity, one may be tempted to criticize the intricacy of the ICNP because it is manmade. However, even deliberately created complexity may be necessary. 1.3 Examples Some actual examples are needed to illustrate the value of the guidelines given in section 1.2: (1) The misinterpretation of Rule 18c that occurred in several recent Requests [23–26, 28–35, 39] and was analysed in 2016 [18] was probably originally caused by not observing Guideline 1 and by instead using other Requests as templates. Rule 18c does not set a time limit for proposing a neotype but for objecting against such a proposal. (2) The misinterpretation of the term ‘nomen periculosum’ observed in some other recent Requests [27, 36, 37, 40, 47] was apparently caused by not considering the Note and the Example attached to Rule 56a(5), which restrict the application of the term to a special case of medical or economic relevance [7, 9, 10]. Adhering to Guidelines 1 and 4 would have prevented these problems. (3) Similarly, the observed misinterpretation of the term ‘nomen perplexum’ [27, 36] seems to be due to not considering the Example attached to Rule 56a(4) and the crossreference to Rule 57c, which indicates that the term solely refers to similarities in spelling [7]. Here observing Guidelines 1, 3 and 4 would have helped. 4 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 (4) Sometimes the reach of Principle 1(1), the aim at the stability of names, is overestimated [37, 40], which seems to be due to not taking into account other clauses within the same Principle, such as Principle 1(4), and disregarding other Principles, such as Principles 8 and 9 [9, 10]. Guidelines 1, 2 and 5 would have prevented these shortcomings. The aim at the stability of names must be understood in the context of other aims, such as the support for taxonomic freedom. (5) Misinterpretation of Principle 1(2) [37], which is concerned with ‘names which may cause error or confusion’, are apparently caused by the same issues and by not considering how the ICNP defines these terms in Rule 56a [9]. Guidelines 1, 2, 4 and 5 would have been useful here. Again, the purpose of Principle 1(2) must be understood in the context of other purposes. (6) Leaving aside Requests, the most classical example for misunderstanding the ICNP is probably the wrong interpretation of the term ‘type’ as indicating that a type is supposed to be typical (or representative) for a taxon [13, 16]. However, as made explicit in Rule 15 [1], the purpose of a nomenclatural type is not to be typical or representative. The ICNP does not govern taxonomy [20], as already indicated in General Consideration 4. In contrast, taxonomic considerations determine the composition of a taxon and thus also determine which of its subunits could be typical or representative [13, 16], hence it would even be impossible for the ICNP to conceive a nomenclatural type in that manner. The misunderstanding probably originates from disregarding the actual usage of the term by the ICNP and simply assuming that an entity called ‘type’ must be ‘typical’ [16], thus contravening Guidelines 1, 4 and 5. The actual purposes of nomenclatural types are quite distinct [1, 13, 48]. Some Judicial Opinions issued in the past may have added to the confusion because they should probably have provided slightly more details on the decision, as, e.g., in the case of Opinion 69 [49], which was needlessly challenged recently [47]. Other Opinions may better have applied a distinct terminology, as, e.g., in Opinion 67 [50], as treated in section 5.2. But Opinions cannot replace the ICNP itself, nor can the Judicial Commission predict all possible misunderstandings. A more thorough reading of the ICNP along the Guidelines given in section 1.2 may well yield more accurate interpretations of the text and prevent the generation of confusion caused by quoting the ICNP out of context. The perceived ambiguity of some statements in the ICNP may also be solved by adhering to those Guidelines. 1.4 Obtaining help Apart from the ICNP itself [1], there are other documents scholars may want to consult when trying to solve a nomenclaturerelated issue and particularly when composing a statement about nomenclature, either within a Request or otherwise. The official publications on prokaryotic nomenclature are listed in Table1. Scholars are advised to consult a suitable selection of these official documents for assistance regarding the interpretation of the ICNP, depending on the particular question. In contrast, even a Request that was granted may contain misinterpretations, as mentioned in section 1.3. The website of the ICSP (www.the-icsp.org) lists publications issued by the committee or associated with the committee. Public debates of the ICSP [51] also contain numerous statements on nomenclature. The ICSP may expand the online platform that was established for public discussions of proposed emendations of the ICNP to enquiries about the interpretation of the current revision of the ICNP. The members of the Editorial Board of the ICNP and the members of the Judicial Commission are listed on the ICSP website and can be contacted individually for help regarding nomenclature. Engaging with these bodies is an excellent opportunity to learn and contribute. Table 1. List of official publications on prokaryotic nomenclature with examples and comments on the scope of each kind of publication Kind of publication Scope ICNP, International Code of Nomenclature of Prokaryotes [1] Authoritative document on prokaryotic nomenclature. Emendations and also newer revisions are regularly published. Approved Lists [44] Starting point of modern prokaryotic nomenclature. Two lists, issued only once in the same publication in 1980. Validation Lists [56, 173–177] Inclusion in a validation list is a necessary condition for a name to be validly published if it does not have an effective publication in the IJSEM. Notification Lists [57, 178–183] Compilations of taxon names proposed in the IJSEM. Are not decisive regarding the valid publication of names but may contain orthographical corrections. Announcements of public discussions of proposed emendations of the ICNP [51, 93] Participation in these debates is an excellent opportunity to learn and contribute. Reports on the outcome of the votes [76, 184, 185] Contain information on the interpretation of selected sections of the ICNP and potentially on its scheduled modifications. Judicial Opinions [4, 5, 7, 9] Contain information on the interpretation of selected sections of the ICNP and on selected aspects of nomenclature. 5 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 In addition, further resources can be of great help, too. On the List of Prokaryotic names with Standing in Nomenclature, also known as LPSN [52], a glossary is found that covers a variety of nomenclaturerelated terms. Additional LPSN pages explain topics of relevance in prokaryotic nomenclature and comprehensively list publications of relevance, including a complete list of Judicial Opinions together with each Request for an Opinion. Researchers are encouraged to make use of such opportunities for obtaining nomenclatural advice. Expert advice itself should be judged according to its adherence to the guidelines given in section 1.2. In the case of regulations actually made by the ICNP it is pertinent to cite the respective General Consideration, Principle, Rule or Recommendation when giving advice. In the case of a statement actually not made by the ICNP it may be difficult to cite a certain clause of the ICNP as proof. However, if an alleged statement made by the ICNP is actually missing from the ICNP one may be able to cite clauses within the ICNP that are in logical conflict with this statement. 1.5 Potential improvements of the ICNP Given the various nomenclaturerelated misjudgements observed in the literature, one may wonder whether the ICNP itself [1] could be improved so as to further decrease the probability of misinterpretations. Here one must not confuse brevity with simplicity: removing regulations from the ICNP might render it superficially more simple, but discarding regulations might also cause uncertainty and thus make the application of the ICNP more difficult. Rather, in line with the guidelines listed in section 1.2, the following kinds of additions might be useful: • Redundancy over inference. Some conclusions can only be inferred by combining distinct sections of the ICNP. By introducing some slight redundancy the need for complicated inferences could be reduced. • More crossreferences. Some misunderstandings can be prevented by introducing crossreferences that connect to other Rules which may easily be overlooked but are relevant for the respective topic. • More caveats. If it is already known that a certain Rule, or a part thereof, is sometimes misinterpreted, it makes sense to add a Note that indicates what is not meant directly to that clause. It must be emphasized, however, that the ICNP already explains certain issues several times; that it already contains cross references; and that it already explicitly clarifies for some aspects of nomenclature how they should not be interpreted, as, e.g., within Principle 4 and Rule 15. For this reason, the potential kinds of additions tentatively suggested here could at most gradually improve the comprehensibility of the text. They would also require specific textual suggestions and subsequent legislation [2]. Emendations of the ICNP such as the ones tentatively suggested here would in most cases probably not have to remove actual ambiguity from the ICNP but just make it less easy for the casual reader to overlook something of relevance. To demonstrate an actual ambiguity of a text it appears to be necessary to provide at least two distinct interpretations of that text which are more or less equally plausible. Other things being equal, this option should become less likely once more information from the text is processed, in accordance with the Guidelines given in section 1.2. Improvements of the ICNP [1] are certainly feasible but ultimately the users of the ICNP are responsible for interpreting it as accurately as possible. In the case of manuscripts submitted to scientific journals, authors, reviewers and editors bear this responsibility. 2. VALID PUBLICATION OF A NAME Taxonomic classification deals with the arrangement of organisms into groups, i.e. taxa, while nomenclature solely deals with the assignment of names to such taxa, given the grouping [1]. For this reason, it is misleading to use terms such as ‘validly described species’ or ‘validly published genus’. There is no status ‘validly described’ under the ICNP, and only names but not taxa can be validly published. This distinction is not a technicality but a crucial difference in perspective [12]. In the same vein, there are no ‘valid names’; a name can be validated by inclusion in a Validation List (Rule 27 Note 1) but such validated names are only a proper subset of the validly published names: not every validly published name was validated. A name proposed in an effective publication in the IJSEM and meeting the other criteria for valid publication does not need to be validated. According to Principle 7, names have no claim to recognition under the ICNP unless they are validly published. If a name has no claim to recognition anyway, it makes no sense to place it on the list of rejected names, a topic that is considered in detail in section 5.2 and other sections below. Hence, like many other nomenclatural aspects, the potential reasons for rejecting a name must be considered in the context of the requirements for valid publication under the ICNP. An argument put forward for rejecting a name may actually indicate that the name is not validly published, particularly in the case of the name of a species or subspecies. This should be considered in a corresponding Request for an Opinion. Issues related to the valid publication of names are thus reiterated in section 2.1 and the subsequent sections, with particular emphasis on the relation to the work of the Judicial Commission. Fig.1 illustrates the relationships between valid publication, legitimacy and rejection of a name, which are nomenclatural status values or actions [1]. Whether or not a name is the correct name as stipulated by Principle 6, Principle 8 and Rule 23a of the ICNP also depends on taxonomic opinion [12]. In settheoretic terms, the set of legitimate names is a proper subset of the set of validly 6 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 published names. That is, all legitimate names are validly published but not all validly published names are legitimate. The set of correct names is a proper subset of the set of legitimate names. That is, all correct names are legitimate but not all legitimate names are regarded as the correct name. An illegitimate name cannot be the correct name of a taxon. The set of rejected names is not a subset of the set of validly published names because some rejected names were not included in the Approved Lists and thus ceased to be validly published [53, 54]. Detailed explanations are provided in sections 2.1–2.5. 2.1 Conditions for valid publication The conditions under which the name of a species or subspecies is regarded as validly published under the ICNP were often reiterated in Judicial Opinions; see, e.g., Opinion 110 [7]. It is evident from the wording of Rule 27 that the publication of a name in the IJSEM or its predecessors, either in a Validation List or in an effective publication directly in the journal, is only a necessary condition but not a sufficient condition for a name to be validly published [55]. It must be emphasized that the nonavailability of type material is not a plausible argument for rejecting a name if this name was never based on type material. This can happen if the name was validly published before 1 January 2001 as indicated in Rule 30(3) [1]. It would be incorrect to assume that the Judicial Commission can actively change the status of a name from being validly published to not being validly published. The Judicial Commission can only recognize a name as not being validly published, and it would not even be needed to involve the Judicial Commission in such cases [56–59], although the Judicial Commission can be asked to clarify the status of a name [60]. This is distinct from the rejection or conservation of a name, which requires an action of the Judicial Commission according to Rules 56a or 56b [1] and not just a clarification. This review of the Judicial Opinions issued after 1980 revealed a high consistency overall, in line with a strict adherence to the ICNP. The Judicial Commission apparently also followed a stare decisis approach, i.e. it used previous decisions as precedents. Opinion 96 [61] stands out because it claimed that the species name Leifsonia rubra Reddy et al. 2003 was validly published although it did not meet the requirements for valid publication given in Rule 30(3b). This appears to be a mistake, as a justification for this decision was not given in the Opinion while arguments to the contrary were presented. As explained in section 1.1, such an outcome may best be regarded as void because it contravenes the ICNP. Although the type strain was apparently deposited in culture collections after the Request [62] was issued, the decision is likely unjustified because the deposits were not available at the time of publication [1]. The appropriate course of action appears to be to validate the name ‘Leifsonia rubra’ by inclusion in a validation list once the necessary deposits were made. The year of valid publication would accordingly be much later, which would in turn affect the priority. This could well be regarded a matter of fairness relative to other names that potentially competed with that name for priority but whose type strains were appropriately deposited. For instance, the name ‘Chlorobaculum thiosulfatiphilum’ [63] was published in the IJSEM in 2003 but validated by inclusion in Validation List No. 204 [64] once typestrain deposits were available, yielding the name Chlorobaculum thiosulfatiphilum Imhoff 2022. 2.2 Valid publication versus legitimacy A legitimate name is a validly published name that does not contravene any Rule. Accordingly, there are some Rules which determine the requirements for valid publication, and there are other Rules with which a validly published name can disagree. Fig. 1. Status of a name under the ICNP and factors influencing this status. Status values and factors that depend on taxonomic opinion are printed in italics and marked with an asterisk. For details see particularly sections 2.1–2.3. Only validly published names can be legitimate (be in accordance with the Rules) or illegitimate (contravene a Rule). Only a legitimate name can be the correct name of a taxon (the name to be applied under the Rules). Yet a name not regarded as the correct name is not illegitimate for this reason, nor can it be rejected for this reason. A rejected name may not be applied to any taxon. Some names placed on the list of rejected names are not validly published, e.g. because they were not included in the Approved Lists. 7 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 Much like valid publication, issues of legitimacy can be clarified by the Judicial Commission but it cannot change the legitimacy of a name, apart from rare cases such as those indicated in Rule 22, which was used in Opinion 119 [9]. Another way to change the legitimacy of a name is a change of the ICNP [1] itself, as treated elsewhere in this paper. Since Rule 30 only mentions requirements at the time of publication, the later loss of single, several or all typestrain deposits would not make a validly published name illegitimate (Rule 23a Note 5) because this loss does not make the name contravene a rule. If the name was indeed illegitimate it could not be rescued by assigning a neotype, nor would there be a real need to reject the name, as it may not be the correct name anyway according to Principle 6 and Rule 23a [1]. Moreover, Rule 30 defines conditions for the valid publication of a name. As reiterated in Opinion 117 [7], if these requirements were not met a name would not be validly published and, accordingly, have no claim to recognition under the ICNP (Fig.1). As legitimacy is a status under the ICNP, one wonders how it should apply to a name that is not validly published [65]. The 2022 revision of the ICNP [45] deals more explicitly with these relationships but it was possible to infer them from previous revisions, too [1]. Conversely, because of the options of assigning a neotype and of rejecting a name for cases in which type strains are lost, this cannot be a matter of legitimacy. Moreover, establishing a neotype according to Rule 18c is not a means of changing the status of a name from not validly published to validly published, as emphasized in Opinions 108 [7] and 113 [9], or from illegitimate to legitimate [1]. 2.3 Legitimate name versus correct name Another potential source of confusion is the distinction between whether or not a name is the correct name, and whether or not a name is legitimate. Rule 23a Note 5 [1] clearly differentiates between a legitimate name (‘in accordance with the Rules’) and a correct name (‘the name which must be adopted for a taxon under the Rules’). Principle 6, the first sentence of Rule 23a, and Rule 23b clarify that being legitimate is a necessary condition but not a sufficient condition for being the correct name. This in turn means that a name that is not the correct name is not illegitimate for that reason (Fig.1). According to General Consideration 4 and Principle 1(4) the ICNP does not rule on taxonomy. Whether or not two taxa with a validly published and legitimate name are considered as heterotypic synonyms is a matter of taxonomic opinion [12], even if it is the currently prevailing taxonomic opinion. If two taxa are considered as heterotypic synonyms, according to Principle 6 and the first sentence of Rule 23a only one of the two names of the taxa can be the correct name. Similarly, if two taxon names are homotypic synonyms derived from the same basonym, they are usually generated to express distinct taxonomic views on the position of a taxon, such as the placement of a species in a genus. Again, a taxonomic choice must be made, and at most one of them can be considered the correct name, depending on that choice [12]. Taxonomic views, on which the ICNP does not rule, can thus play a role in determining the correct name (Fig.1), since position and circumscription of a taxon are matters of taxonomic opinion. In contrast, the other factors which determine the correct name, such as legitimacy [7], are solely a matter of nomenclature (Fig.1). This also indicates that a name that is not the correct name is not illegitimate for that reason. Position and circumscription of a taxon are chosen according to taxonomic opinion. The Rules of nomenclature then determine the correct name, if any, for that taxon with a given position and circumscription (Fig.1). Selecting a name that is not the correct name as the name for the taxon would certainly contravene the ICNP. However, this does not make that name illegitimate, nor can a name that is not regarded as the correct name be placed on the list of rejected names for that reason. Rather, a validly published and legitimate name that is not regarded as the correct name must simply be regarded as a synonym, either a later synonym or a synonym whose counterpart has been conserved over it by the Judicial Commission (Fig.1); see also section 7.2. Whether or not two taxon names are synonyms is solely determined via the positioning of the nomenclatural types of the two taxa, as indicated in Rule 24a Note 3 [1]. In a given hierarchical classification each taxon or strain can be positioned within at most one taxon of a certain category. This also implies that each nomenclatural type can be positioned within at most one taxon of a certain category. For this reason, their cannot be partial synonyms, and the ICNP does indeed not support the concept [1]. A name regarded as a synonym can still be the nomenclatural type according to Rule 15 [66]. This would not be possible if the name was illegitimate, since according to Rule 51a an illegitimate name may not be used [1]. Rules 20a and 21a explain that this extends to the use as nomenclatural type. This again points at the distinction between legitimacy and correctness: an illegitimate name may not serve as nomenclatural type but a validly published and legitimate name that is not the correct name may serve as type. The 2022 revision of the ICNP [45] deals more explicitly with these relationships but it was possible to infer them from previous revisions, too [1]. Among a set of homotypic synonyms derived from the same basonym, the last one that is validly published and legitimate is not automatically the correct name [1, 66, 67]. Similarly, the views on heterotypic synonymy that were published last need not be followed. More recent taxonomic studies may indeed be based on more or better data, which may argue for adopting their view. However, the differences to previous taxonomic arrangements may as well be just based on distinct taxonomic concepts, whereas the mere use of the same data may have yielded the same taxonomic classification as before [67, 68]. Using a previously published 8 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 taxonomic arrangement instead of the last one that was put forward in the literature is never arbitrary but just conservative. Be that as it may, neither the ICNP nor the Judicial Commission rule on taxonomic views; see also section 6.2. 2.4 Names validly published until 2000 Whether or not a name is validly published due to its inclusion in the Approved Lists [44] is also often of relevance in the context of a Request for an Opinion [69]. Opinion 95 [70] ruled that names with an effective publication prior to 1980 and not included in the Approved Lists are not validly published even if they should have been included in the Approved Lists; for an alternative outcome see Opinion 83 [71]. Opinion 58 [72] confirmed for the first time that the nomenclatural types chosen in the Approved Lists supersede any others that were previously in use for the same taxon but that the Judicial Commission can still amend these choices. Rule 30(3)(b) indicates that as ‘of 1 January 2001, the description of […] new combinations previously represented by viable cultures must include the designation of a type strain […] deposited in at least two publicly accessible culture collections in different countries’ [1]. This has the consequence that new combinations cannot be validly published if their basonym was based on a type strain and this strain is not available, or not available any more, from culture collections in at least two distinct countries. This issue mainly affects names of species or subspecies validly published before 1 January 2001 because until then only a single typestrain deposit was sufficient. The situation is probably best addressed by the exchange of cultures between culture collections, similar to the kind of actions reported in Opinion 81 [73]. However, if a name validly published before 1 January 2001 was based instead on a preserved specimen, description or illustration, the ICNP appears to permit the proposal of a new combination without the need for a deposit of the type strain. The ICNP only briefly explains the term basonym as the original name on which a new combination (which retains an epithet) or, rarely, a nomen novum (which does not retain the epithet) is based. In conjunction with Rule 34b, which clarifies that the ‘original author’ should be cited in parentheses, it is obvious that the basonym is the name which originally used the epithet. That is, a basonym does not itself have a basonym. The Approved Lists [44] include a variety of names whose basonym was not included although the basonym is referred to by citing its authors in parentheses. For instance, Amoebobacter pendens (Molisch 1906) Pfennig and Trüper 1971 (Approved Lists 1980) [44, 74] is a validly published name due to its inclusion in the Approved Lists but its basonym ‘Rhodothece pendens’ Molisch 1906 [44, 75] is not validly published. Thus, a basonym has either to be validly published or must have been used as basonym in the Approved Lists. 2.5 Names of Cyanobacteria The integration of the names of Cyanobacteria [76, 77] into the ICNP raised questions with respect to the valid publication of new combinations proposed for such names. These emendations of the ICNP implicitly introduced a distinction between names that are validly published under the ICNP because they are validly published under another code on the one hand, and all other names validly published under the ICNP on the other hand. For the purpose of the following discussion, the latter, which still form the majority, will be called ‘directly’ validly published under the ICNP. The new addition [76] to Rule 30(4) reads: ‘Names of taxa of Cyanobacteria validly published in conformity with the Rules of the International Code of Nomenclature for algae, fungi, and plants are also validly published in conformity with the Rules of the International Code of Nomenclature of Prokaryotes (see General Consideration 5).’ Similar provisions were made for the recognition of the nomenclatural type of species and subspecies whose names were directly validly published under the International Code of Nomenclature for algae, fungi, and plants (ICN) in Rule 18a. However, none of these regulations apply to new combinations which are attempted to be validly published directly under the ICNP, even if these are names of Cyanobacteria. Since the demands for the nomenclatural types are distinct between the ICN [78] and the ICNP [1], particularly as of 1 January 2001, an attempt to validly publish a new combination directly under the ICNP for a basonym validly published for a taxon of Cyanobacteria directly under the ICN is expected to fail since Rule 30(3) remained asis. The solution appears to be to try to validly publish a new combination directly under the ICN whenever the direct valid publication of its basonym was also made under the ICN. If this succeeds (according to the Articles of the ICN), the new combination will automatically be regarded as validly published under the ICNP, too, based on the new regulations [76]. In general, in order to be able to easily determine whether the requirements for valid publication were met under either code, it seems beneficial to mark names of Cyanobacteria directly validly published under the ICN as being validly published under the ICN instead of under the ICNP, and vice versa. Exactly one of the two codes should be indicated along with the description. Lumping may apparently cause a loss of information. Nomenclatural issues with names originally validly published under the ICN should not normally be reported to the Judicial Commission of the ICSP but treated according to the regulations of the ICN [78]. 9 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 3. PROPOSALS THAT ARE NOT SUITABLE AS REQUESTS FOR AN OPINION There are a variety of nomenclaturerelated actions into which the Judicial Commission needs not be involved or at least needs not directly be involved. 3.1 Proposals for modifying the ICNP These should not be submitted as a Request. A Request makes sense for clarifying the meaning of the current revision of the ICNP [1, 45] regarding a certain issue, or for taking actions such as the conservation or rejection of names (which must also be made in compliance with the ICNP). In contrast, authors are advised to avoid the term ‘Request’ in the title of a manuscript that suggests an emendation of the ICSP. A formal proposal to emend the ICNP as outlined in Article 13(b) of the statutes of the ICSP [2] should be made, marked distinctly from a Request and be placed into the corresponding category of the IJSEM [48, 65, 77, 79–92]. Sometimes proposals for changing the ICNP that are directed to the Judicial Commission are submitted to the IJSEM. The Judicial Commission would then issue an Opinion that may or may not recommend a corresponding change to the ICNP. This step is unnecessary, however, particularly because this step alone would not yield a change to the ICNP, nor would it directly initiate such a change [2]. Moreover, members of the Judicial Commission could comment on the proposal anyway, namely during the subsequent public ICSP debate about the proposal [51]. Members of the ICSP, particularly members of the Editorial Board of the ICNP or members of the Judicial Commission, could also be informally asked for advice prior to submission of a corresponding manuscript, either personally or via one of the channels described in section 1.4. A paper that proposes an emendation of the ICNP should include at least one proposal for the wording the authors wish to have added to the ICNP, or the wording alternative to the wording used in the current revision. The wordings of all suggested changes of the ICNP should be clearly highlighted as such to distinguish them from the rest of the manuscript. If the authors have just one proposal for each suggested emendation of the ICNP, they should publish only this one. If the authors believe that some wordings may be more controversial than others, or just provide an alternative solution of interest, they should provide several ones and highlight the differences [77, 89]. In either case, providing the wording in the publication itself considerably speeds up the processing [51, 93] and increases the probability that the ICNP is emended to as to accurately reflect the goals of the authors. The best way to ensure this is that the authors phrase the intended text themselves. Authors of proposals for emending the ICNP are strongly advised to search for other sections of the ICNP which could logically contradict their proposed wordings, including definitions given in an Appendix of the ICNP. One should avoid at all cost to introduce wordings into the ICNP that logically contradict other sections of the ICNP, unless these are only of historical interest. In order to properly implement a certain idea, changes at several locations within the ICNP may be necessary [65, 81, 88]. Particularly if several changes are proposed, the format should follow the one used in the latest ICSP debates [51, 93]. That is, a tabular format is advisable with the old text in one column, its newly proposed counterpart in another column, and optional comments in a third column. 3.2 Designation of a type strain in place of a preserved specimen, description or illustration The designation of a type strain for a name validly published before 1 January 2001 that was based on a preserved specimen, description or illustration according to Rule 18a(1) should not be submitted as Request. Rather, such a move [94] must be made as described in Rule 18f [1]. The ICNP does not mention a mechanism by which the Judicial Commission would directly get involved in such a case. As noted in Judicial Opinion 80 [95], ‘a name (epithet) can only be conserved over another name (epithet) or in combination with a particular circumscription’. Accordingly, the Judicial Commission could be requested to conserve a name with a type strain distinct from the one that replaced the preserved specimen, description or illustration, but such an action is not normally needed. Note that a type strain that replaces a preserved specimen, description or illustration is not a neotype strain. Also note that the loss of a type strain does not mean that the description replaces it as the nomenclatural type; the description may only serve to facilitate the search for a neotype strain as indicated in Rule 18c [1]. As for the rejection of names, the nonavailability of a type strain is not a plausible argument for rejecting a name if this name was never based on a type strain. Proper arguments for rejecting a name are treated in several sections below. 3.3 Proposals for assigning a neotype strain These should not be submitted as a Request. Instead, Rule 18c must be followed; see also Rule 19. The Judicial Commission would get involved only in the case of an objection (Rule 18c) or according to Rule 18e [1]. Sometimes the assignment of a neotype is unnecessarily issued as a Request [96, 97]. Opinion 102 [5] granted such as Request, Opinion 100 [5] denied another one. However, objections can be raised during the 2- year period stipulated by 18c instead. This is preferable to requesting the conservation of a name with a distinct type strain or neotype strain afterwards, although such a move is possible [95, 98]. 16 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 25. Podkopaeva D, Grabovich M, Kuever J, Lysenko AM, Tourova TP, etal. Proposal of Spirillum winogradskyi sp. nov., a novel microaerophilic species, an emended description of the genus Spirillum and Request for an Opinion regarding the status of the species Spirillum volutans Ehrenberg 1832. Int J Syst Evol Microbiol 2009;59:2916–2920. 26. Oggerin M, Rubio V, Marín I, Arahal DR. The status of the species Beijerinckia fluminensis Döbereiner and Ruschel 1958. Request for an Opinion. Int J Syst Evol Microbiol 2011;61:1757–1759. 27. Garrity GM. Conservation of Rhodococcus equi (Magnusson 1923) Goodfellow and Alderson 1977 and rejection of Corynebacterium hoagii (Morse 1912) Eberson 1918. Int J Syst Evol Microbiol 2014;64:311–312. 28. Lai Q, Li C, Shao Z. The status of the species Hyphomonas rosenbergii Weiner et al. 2000. Request for an Opinion. Int J Syst Evol Microbiol 2015;65:321. 29. Branquinho R, Klein G, Kämpfer P, Peixe LV. The status of the species Bacillus aerophilus and Bacillus stratosphericus. Request for an Opinion. Int J Syst Evol Microbiol 2015;65:1101. 30. Dunlap CA. The status of the species Bacillus aerius. Request for an Opinion. Int J Syst Evol Microbiol 2015;65:2341. 31. Liu Y, Ramesh Kumar N, Lai Q, Du J, Dobritsa AP, etal. Identification of strains Bacillus aerophilus MTCC 7304T as Bacillus altitudinis and Bacillus stratosphericus MTCC 7305T as a Proteus sp. and the status of the species Bacillus aerius Shivaji et al. 2006. Request for an Opinion. Int J Syst Evol Microbiol 2015;65:3228–3231. 32. Velázquez E, Flores- Félix JD, Sánchez- Juanes F, González- Buitrago JM, Peix A. The status of the genus Seliberia Aristovskaya and Parinkina 1963 (Approved Lists 1980) and the species Seliberia stellate Aristovskaya and Parinkina 1963 (Approved Lists 1980). Request for an Opinion. Int J Syst Evol Microbiol 2015;65:2337–2340. 33. Rameshkumar N. The status of the species Shewanella irciniae Lee et al. 2006. Request for an Opinion. Int J Syst Evol Microbiol 2015;65:2774. 34. Kämpfer P, Doijad S, Chakraborty T, Glaeser SP. The status of the species Enterobacter siamensis Khunthongpan et al. 2014. Request for an Opinion. Int J Syst Evol Microbiol 2016;66:524–525. 35. Kimura ZI, Hoshino T, Murakami K. The status of the species Moorella thermoautotrophica Wiegel et al. 1981. Request for an Opinion. Int J Syst Evol Microbiol 2016;66:3249–3251. 36. Vázquez- Boland JA, Scortti M, Meijer WG. Conservation of Rhodococcus equi (Magnusson 1923) Goodfellow and Alderson 1977 and rejection of Rhodococcus hoagii (Morse 1912) Kämpfer et al. 2014. Int J Syst Evol Microbiol 2020;70:3572–3576. 37. Balish M, Bertaccini A, Blanchard A, Brown D, Browning G, etal. Recommended rejection of the names Malacoplasma gen. nov., Mesomycoplasma gen. nov., Metamycoplasma gen. nov., Metamycoplasmataceae fam. nov., Mycoplasmoidaceae fam. nov., Mycoplasmoidales ord. nov., Mycoplasmoides gen. nov., Mycoplasmopsis gen. nov. [Gupta, Sawnani, Adeolu, Alnajar and Oren 2018] and all proposed species comb. nov. placed therein. Int J Syst Evol Microbiol 2019;69:3650–3653. 38. Ribeiro TG, Rocha J, Ksiezarek M, Perovic SU, Grosso F, et al. The status of the species Lactobacillus fornicalis Dicks et al. 2000. Request for an Opinion. Int J Syst Evol Microbiol 2020;70:3953–3954. 39. Glaeser SP, Pulami D, Blom J, Eisenberg T, Goesmann A, etal. The status of the genus Prolinoborus (Pot et al. 1992) and the species Prolinoborus fasciculus (Pot et al. 1992). Int J Syst Evol Microbiol 2020;70:5165–5171. 40. Margos G, Castillo- Ramirez S, Cutler S, Dessau RB, Eikeland R, etal. Rejection of the name Borreliella and all proposed species comb. nov. placed therein. Int J Syst Evol Microbiol 2020;70:3577–3581. 41. Tindall BJ. What ever happened to Thermomicrobium fosteri Phillips and Perry 1976? Int J Syst Evol Microbiol 2014;64:1065–1067. 42. Yassin AF, Spröer C, Pukall R, Schumann P. The status of the species Actinobaculum massiliense (Greub and Raoult 2006). Request for an Opinion. Int J Syst Evol Microbiol 2015;65:1102–1103. 43. Farmer III JJ, Holmes B. Conservation of the name Aeromonas eucrenophila over the name Aeromonas punctata for the organism based on type stain NCMB 74T and universally defined as ‘Aeromonas DNA hybridization group 6’. Int J Syst Evol Microbiol 2020;70:2158–2162. 44. Skerman VBD, McGowan V, Sneath PHA. Approved Lists of Bacterial Names. Int J Syst Bacteriol 1980;30:225–420. 45. Oren A, Arahal DR, Göker M, Moore ERB, Rossello- Mora R, et al. (n.d.) International Code of Nomenclature of Prokaryotes – Prokaryotic Code (2022 Revision). Int J Syst Evol Microbiol:in press. 46. Tindall BJ. Names at the rank of class, subclass and order, their typification and current status: Supplementary information to Opinion 79. Judicial Commission of the International Committee on Systematics of Prokaryotes. Int J Syst Evol Microbiol 2014;64:3599–3602. 47. Dobritsa AP, Kutumbaka KK, Samadpour M. Reclassification of Eubacterium combesii and discrepancies in the nomenclature of botulinum neurotoxinproducing clostridia: Challenging Opinion 69. Request for an Opinion. Int J Syst Evol Microbiol 2018;68:3068–3075. 48. Tindall BJ. Updating Rule 15 of the International Code of Nomenclature of Bacteria. Int J Syst Evol Microbiol 2015;65:2766–2768. 49. Judicial Commission. Opinion 69. Rejection of Clostridium putrificum and conservation of Clostridium botulinum and Clostridium sporogenes. Int J Syst Bacteriol 1999;49:339. 50. Judicial Commission. Opinion 67. Rejection of the name Citrobacter diversus Werkman and Gillen 1932. Int J Syst Bacteriol 1993;43:392. 51. Oren A, Arahal DR, Rosselló-Móra R, Sutcliffe IC, Moore ERB. Public discussion on a proposed revision of the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2021;71:4918. 52. Meier- Kolthoff JP, Carbasse JS, Peinado- Olarte RL, Göker M. TYGS and LPSN: a database tandem for fast and reliable genomebased classification and nomenclature of prokaryotes. Nucleic Acids Res 2022;50:D801–D807. 53. Judicial Commission. Opinion 54: Rejection of the species name Pseudomonas denitrificans (Christensen) Bergey et al. 1923: Judicial Commission of the International Committee on Systematic Bacteriology. Int J Syst Bacteriol 1982;32:466. 54. Judicial Commission. Opinion 55: Rejection of the species name Mycobacterium aquae Jenkins et al. 1972: Judicial Commission of the International Committee on Systematic Bacteriology. Int J Syst Bacteriol 1982;32:467. 55. Tindall BJ. On the valid publication of names and combinations. Int J Syst Evol Microbiol 2015;65:3226–3227. 56. Euzéby JP. Validation List no. 148. List of new names and new combinations previously effectively, but not validly, published. Int J Syst Evol Microbiol 2012;62:2549–2554. 57. Euzéby JP. Notification that new names and new combinations have appeared in volume 58, part 1, of the IJSEM. Int J Syst Evol Microbiol 2008;58:747–748. 58. Oren A, Garrity GM, Spring S, Onrust L, Petzoldt D, et al. Valid publication of the names Caecibacterium and Caecibacterium sporoformans. Int J Syst Evol Microbiol 2019;69:452–453. 59. Tindall BJ. On the nomenclatural types of Methylothermus thermalis Tsubota et al. 2005, Methylothermus Tsubota et al. 2005 and Methylothermaceae Hirayama et al. 2014, their status under the International Code of Nomenclature of Prokaryotes and valid publication of the names Methylothermus gen. nov., Methylothermus subterraneus Hirayama et al. and Methylothermaceae Hirayama et al. Int J Syst Evol Microbiol 2019;69:1890–1891. 60. Dellaglio F, Klein G. Rejection of Lactobacillus panis (Wiese et al. 1996). Request for an Opinion. Int J Syst Evol Microbiol 1997;47:910. 17 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 61. Tindall BJ. The properties given at the time of publication for the designated type strain of Leifsonia rubra Reddy et al. 2003, CMS 76r, do not correspond with those of MTCC 4210, DSM 15304, CIP 107783 and JCM 12471 that are deposited as representing the type strain: Opinion 96. Int J Syst Evol Microbiol 2014;64:3593–3594. 62. An SY, Yokota A. The status of the species Leifsonia rubra Reddy et al. 2003. Request for an Opinion. Int J Syst Evol Microbiol 2007;57:1163. 63. Imhoff JF. Phylogenetic taxonomy of the family Chlorobiaceae on the basis of 16S rRNA and fmo (Fenna- Matthews- Olson protein) gene sequences. Int J Syst Evol Microbiol 2003;53:941–951. 64. Oren A, Garrity GM. Valid publication of new names and new combinations effectively published outside the IJSEM. Int J Syst Evol Microbiol 2022;72:5260. 65. Tindall BJ. The relationship of validly published names to legitimate and illegitimate names in the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2016;66:4905–4906. 66. Tindall BJ. Agrobacterium radiobacter (Beijerinck and van Delden 1902) Conn 1942 has priority over Agrobacterium tumefaciens (Smith and Townsend 1907) Conn 1942 when the two are treated as members of the same species based on the principle of priority and Rule 23a, Note 1 as applied to the corresponding specific epithets. Opinion 94. Judicial Commission of the International Committee on Systematics of Prokaryotes. Int J Syst Evol Microbiol 2014;64:3590–3592. 67. Margos G, Wormser GP, Schwartz I, Markowicz M, Henningsson AJ, etal. Evidence of taxonomic bias in public databases: the example of the genus Borrelia. Ticks Tick Borne Dis 2022;13:101994. 68. Göker M. What can genome analysis offer for bacteria? In: Bridge P, Smith D and Stackebrandt E (eds). Trends in the Systematics of Bacteria and Fungi. Wallingford: CAB International; 2021. pp. 255–281. 69. Lang E, Spröer C. Replacement of ATCC 25944T, the current type strain of Melittangium lichenicola, with ATCC 25946. Request for an Opinion. Int J Syst Evol Microbiol 2008;58:2991–2992. 70. Tindall BJ. The combinations Lysobacter enzymogenes subsp. enzymogenes Christensen and Cook 1978, L. enzymogenes subsp. cookii Christensen 1978 and Streptococcus casseliflavus (Mundt and Graham 1968) Vaughan et al. 1979 were in accordance with the International Code of Nomenclature of Bacteria at the time of publication in the International Journal of Systematic Bacteriology, but are not to be considered to be included on the Approved Lists of Bacterial Names. Opinion 95: Judicial Commission of the International Committee on Systematics of Prokaryotes. Int J Syst Evol Microbiol 2014;64:3920–3921. 71. Tindall BJ. The subgenus names Moraxella and Branhamella (in the genus Moraxella) are not in accordance with the International Code of Nomenclature of Bacteria and are therefore not validly published: Supplementary information to Opinion 83. Judicial Commission of the International Committee on Systematics of Prokaryotes. Int J Syst Evol Microbiol 2014;64:3595–3596. 72. Judicial Commission. Opinion 58: Confirmation of the types in the Approved Lists as nomenclatural types including recognition of Nocardia asteroides (Eppinger 1891) Blanchard 1896 and Pasteurella multocida (Lehmann and Neumann 1899) Rosenbusch and Merchant 1939 as the respective type species of the genera Nocardia and Pasteurella and rejection of the species name Pasteurella gallicida (Burrill 1883) Buchanan 1925: Judicial Commission of the International Committee on Systematic Bacteriology. Int J Syst Bacteriol 1985;35:538. 73. Judicial Commission. Status of strains that contravene Rules 27 (3) and 30 of the International Code of Nomenclature of Bacteria. Opinion 81. Int J Syst Evol Microbiol 2008;58:1755–1763. 74. Pfennig N, Trüper HG. New nomenclatural combinations in the phototrophic sulfur bacteria. Int J Syst Bacteriol 1971;21:11–14. 75. Molisch H. Zwei neue Purpurbakterien mit Schwebekörperchen. Botanische Zeitung Abteilung I 1906;64:223–232. 76. Oren A, Arahal DR, Rosselló-Móra R, Sutcliffe IC, Moore ERB. Emendation of General Consideration 5 and Rules 18a, 24a and 30 of the International Code of Nomenclature of Prokaryotes to resolve the status of the Cyanobacteria in the prokaryotic nomenclature. Int J Syst Evol Microbiol 2021;71:4939. 77. Oren A. Three alternative proposals to emend the Rules of the International Code of Nomenclature of Prokaryotes to resolve the status of the Cyanobacteria in the prokaryotic nomenclature. Int J Syst Evol Microbiol 2020;70:4406–4408. 78. Turland N, Wiersema J, Barrie F, Greuter W, Hawksworth D, etal. International Code of Nomenclature for algae, fungi, and plants. Königstein im Taunus: Koeltz Botanical Books, 2018. 79. Euzéby JP. Proposal to amend Rule 61 of the International Code of Nomenclature of Bacteria (1990 revision). Int J Syst Bacteriol 1998;48:611–612. 80. Oren A, Garrity GM, Schink B. Proposal to modify Rule 6, Rule 10a, and Rule 12c of the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2014;64:1452–1453. 81. Oren A, da Costa MS, Garrity GM, Rainey FA, Rosselló-Móra R, etal. Proposal to include the rank of phylum in the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2015;65:4284–4287. 82. Oren A, Garrity GM. The status of the Notes in the International Code of Nomenclature of Prokaryotes: proposal to emend General Consideration 6. Int J Syst Evol Microbiol 2016;66:3305–3306. 83. Tindall BJ. The undesirable retroactive changes to Rule 8 of the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2016;66:4895–4896. 84. Whitman WB. Modest proposals to expand the type material for naming of prokaryotes. Int J Syst Evol Microbiol 2016;66:2108–2112. 85. Oren A. Proposal to modify Rule 10a and to delete Recommendation 10a(3) from the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2017;67:3683–3684. 86. Oren A, Chuvochina M, Schink B. The use of Greek and Latin prepositions and prefixes in compound names: proposed emendation of Appendix 9 of the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2019;69:1831–1832. 87. Tindall BJ. Names above the rank of genus; the radical approach. Int J Syst Evol Microbiol 2019;69:1833–1834. 88. Tindall BJ. An analysis of the term ‘standing in nomenclature’, as used in the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2019;69:2166–2168. 89. Tindall BJ. Clarifying the definition and role of effective publication in the International Code of Nomenclature of Prokaryotes with proposals to make changes. Int J Syst Evol Microbiol 2019;69:2602–2605. 90. Tindall BJ. Rule 24b of the International Code of Nomenclature of Prokaryotes and regulating the priority of names and epithets considered to be associated with heterotypic synonyms. Int J Syst Evol Microbiol 2019;69:3980–3983. 91. Whitman WB, Sutcliffe IC, Rossello- Mora R. Proposal for changes in the International Code of Nomenclature of Prokaryotes: granting priority to Candidatus names. Int J Syst Evol Microbiol 2019;69:2174–2175. 92. Oren A, Schink B. Use of Greek in the prokaryotic nomenclature: proposal to change Principle 3, Recommendation 6, Rule 7, Rule 65 and Appendix 9 of the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2020;70:3559–3560. 93. Oren A, Arahal DR, Rosselló-Móra R, Sutcliffe IC, Moore ERB. Preparing a revision of the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2021;71:4598. 94. Nouioui I, Ghodhbane- Gtari F, Montero- Calasanz MDC, Göker M, Meier- Kolthoff JP, et al. Proposal of a type strain for Frankia alni (Woronin 1866) Von Tubeuf 1895, emended 18 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 description of Frankia alni, and recognition of Frankia casuarinae sp. nov. and Frankia elaeagni sp. nov. Int J Syst Evol Microbiol 2016;66:5201–5210. 95. Judicial Commission. The type species of the genus Salmonella Lignieres 1900 is Salmonella enterica (ex Kauffmann and Edwards 1952) Le Minor and Popoff 1987, with the type strain LT2T, and conservation of the epithet enterica in Salmonella enterica over all earlier epithets that may be applied to this species. Opinion 80. Int J Syst Evol Microbiol 2005;55:519–520. 96. Lang E, Stackebrandt E. Emended descriptions of the genera Myxococcus and Corallococcus, typification of the species Myxococcus stipitatus and Myxococcus macrosporus and a proposal that they be represented by neotype strains. Request for an Opinion. Int J Syst Evol Microbiol 2009;59:2122–2128. 97. Duncan SH, Flint HJ. Proposal of a neotype strain (A1- 86) for Eubacterium rectale. Request for an Opinion. Int J Syst Evol Microbiol 2008;58:1735–1736. 98. Judicial Commission. Replacement of strain NCTC 4175, since 1963 the neotype strain of Proteus vulgaris, with strain ATCC 29905 - Opinion 70. Int J Syst Bacteriol 1999;49:1949. 99. Judicial Commission. Strain NCIMB 13488 may serve as the type strain of Halorubrum trapanicum. Opinion 74. Int J Syst Evol Microbiol 2003;53:933. 100. Judicial Commission. Rejection of the genus name Pelczaria with the species Pelczaria aurantia Poston 1994. Opinion 78. Int J Syst Evol Microbiol 2005;55:515. 101. Tindall BJ. The consequences of Bacillus axarquiensis Ruiz- García et al. 2005, Bacillus malacitensis Ruiz- García et al. 2005 and Brevibacterium halotolerans Delaporte and Sasson 1967 (Approved Lists 1980) being treated as heterotypic synonyms. Int J Syst Evol Microbiol 2017;67:175–176. 102. Tindall BJ. Marinobacterium iners (Iizuka and Komagata 1964) comb. nov. arising from the synonymy of Marinobacterium georgiense González et al. 1997 and Pseudomonas iners Iizuka and Komagata 1964 (Approved Lists 1980). Curr Microbiol 2019;76:1128–1129. 103. Tindall BJ. Marinobacter nauticus (Baumann et al. 1972) comb. nov. arising from instances of synonymy and the incorrect interpretation of the International Code of Nomenclature of Prokaryotes. Arch Microbiol 2020;202:657–663. 104. Judicial Commission. Paenibacillus durus (Collins et al. 1994, formerly Clostridium durum Smith and Cato 1974) has priority over Paenibacillus azotofixans (Seldin et al. 1984). Opinion 73. Int J Syst Evol Microbiol 2003;53:931. 105. Judicial Commission. The type strain of Lactobacillus casei is ATCC 393, ATCC 334 cannot serve as the type because it represents a different taxon, the name Lactobacillus paracasei and its subspecies names are not rejected and the revival of the name ‘Lactobacillus zeae’ contravenes Rules 51b (1) and (2) of the International Code of Nomenclature of Bacteria. Opinion 82. Int J Syst Evol Microbiol 2008;58:1764–1765. 106. Van Loghem JJ. The classification of the plaguebacillus. Antonie van Leeuwenhoek 1944;10:15–16. 107. Bercovier H, Mollaret HH, Alonso JM, Brault J, Fanning GR, etal. Intra- and interspecies relatedness of Yersinia pestis by DNA hybridization and its relationship to Yersinia pseudotuberculosis. Curr Microbiol 1980;4:225–229. 108. Associate Editor. Validation of the publication of new names and new combinations previously effectively published outside the IJSB. List No. 7. Int J Syst Bacteriol 1981;31:382–383. 109. Judicial Commission. Opinion 60: rejection of the name Yersinia pseudotuberculosis subsp. pestis (van Loghem) Bercovier et al. 1981 and conservation of the name Yersinia pestis (Lehmann and Neumann) van Loghem 1944 for the plague bacillus: Judicial Commission of the International Committee on Systematic Bacteriology. Int J Syst Bacteriol 1985;35:540. 110. Judicial Commission. Opinion 55. Rejection of the species name Mycobacterium aquae Jenkins et al 1972. Int J Syst Bacteriol 1982;1982:32–467. 111. Judicial Commission. Opinion 56. Rejection of the species name Peptococcus anaerobius (Hamm) Douglas 1957. Int J Syst Bacteriol 1982;32:468. 112. Tindall BJ. The genus name Methanothrix Huser et al. 1983 and the species combination Methanothrix soehngenii Huser et al. 1983 do not contravene Rule 31a and are not to be considered as rejected names, the genus name Methanosaeta Patel and Sprott 1990 refers to the same taxon as Methanothrix soehngenii Huser et al. 1983 and the species combination Methanothrix thermophila Kamagata et al. 1992 is rejected: Supplementary information to Opinion 75. Judicial Commission of the International Committee on Systematics of Prokaryotes. Int J Syst Evol Microbiol 2014;64:3597–3598. 113. Judicial Commission. Rejection of the genus name Methanothrix with the species Methanothrix soehngenii Huser et al. 1983 and transfer of Methanothrix thermophila Kamagata et al. 1992 to the genus Methanosaeta as Methanosaeta thermophila comb. nov. Opinion 75. Int J Syst Evol Microbiol 2008;58:1753–1754. 114. Tindall BJ. The status of names whose nomenclatural types are based on strains deposited solely for patent purposes. Int J Syst Evol Microbiol 2019;69:2616–2620. 115. Tindall BJ. Clarification of access regulations to genetic resources that are subject to the sovereign rights of sovereign states and the deposit of nomenclatural types under the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2020;70:317–320. 116. Tindall BJ. Confirmation of deposit, but confirmation of what? Int J Syst Evol Microbiol 2008;58:1785–1787. 117. Judicial Commission. Strain DSM 6035 is the type strain of Lactobacillus panis (Wiese et al. 1996). Opinion 72. Int J Syst Evol Microbiol 2003;53:929. 118. Judicial Commission. Opinion 63: Rejection of the type species Methanosarcina methanica (Approved Lists, 1980) and conservation of the genus Methanosarcina (Approved Lists, 1980) emend. Mah and Kuhn 1984 with Methanosarcina barkeri (Approved Lists, 1980) as the type species. Int J Syst Bacteriol 1986;36:492. 119. Judicial Commission. Opinion 59: Designation of NCIB 11664 in place of ATCC 23767 (NCIB 4112) as the type strain of Acetobacter aceti subsp. xylinum (Brown 1886) De Ley and Frateur 1974. Int J Syst Bacteriol 1985;35:539. 120. Judicial Commission. Opinion 64: Designation of strain MF (DSM 1535) in place of strain M.o.H. (DSM 863) as the type strain of Methanobacterium formicicum Schnellen 1947, and designation of strain M.o.H. (DSM 863) as the type strain of Methanobacterium bryantii (Balch and Wolfe in Balch, Fox, Magrum, Woese, and Wolfe 1979, 284) Boone 1987, 173. Int J Syst Bacteriol 1992;42:654. 121. Judicial Commission. Opinion 65: Designation of strain VPI D 19B- 28 (ATCC 35185) in place of strain VPI 10068 (ATCC 33150) as the type strain of Selenomonas sputigena (Flügge 1886) Boskamp 1922. Int J Syst Bacteriol 1992;42:655. 122. Judicial Commission. Opinion 66: Designation of strain NS 51 (NCTC 12261) in place of strain NCTC 3165 as the type strain of Streptococcus mitis Andrewes and Horder 1906. Int J Syst Bacteriol 1993;43:391. 123. Judicial Commission. Opinion 68: Designation of strain B213c (DSM 20284) in place of strain NCDO 1859 as the type strain of Pediococcus acidilactici Lindner 1887. Int J Syst Bacteriol 1996;46:835. 124. Judicial Commission. Strain NBRC (formerly IFO) 3782 is the type strain of Streptomyces rameus Shibata 1959. Opinion 76. Int J Syst Evol Microbiol 2005;55:511. 125. Judicial Commission. Corynebacterium ilicis is typified by ICMP 2608 =ICPB CI144, Arthrobacter ilicis is typified by DSM 20138 =ATCC 14264 =NCPPB 1228 and the two are not homotypic synonyms, and clarification of the authorship of these two species. Opinion 87. Int J Syst Evol Microbiol 2008;58:1976–1978. 19 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 126. Tindall BJ. ATCC 43642 replaces ATCC 23581 as the type strain of Leptospira interrogans (Stimson 1907) Wenyon 1926. Opinion 91. Judicial Commission of the International Committee on Systematics of Prokaryotes. Int J Syst Evol Microbiol 2014;64:3584–3585. 127. Judicial Commission. Opinion 61: Rejection of the type strain of Pasteuria ramosa (ATCC 27377) and conservation of the species Pasteuria ramosa Metchnikoff 1888 on the basis of the type descriptive material. Int J Syst Bacteriol 1986;36:119. 128. Tindall BJ. The designated type strain of Pseudomonas halophila Fendrich 1989 is DSM 3051, the designated type strain of Halovibrio variabilis Fendrich 1989 is DSM 3050, the new name Halomonas utahensis (Fendrich 1989) Sorokin and Tindall 2006 is created for the species represented by DSM 3051 when treated as a member of the genus Halomonas, the combination Halomonas variabilis (Fendrich 1989) Dobson and Franzmann 1996 is rejected, and the combination Halovibrio denitrificans Sorokin et al. 2006 is validly published with an emendation of the description of the genus Halovibrio Fendrich 1989 emend. Sorokin et al. 2006. Opinion 93. Judicial Commission of the International Committee on Systematics of Prokaryotes. Int J Syst Evol Microbiol 2014;64:3588–3589. 129. Tindall BJ. The status of the name Lactobacillus rogosae Holdeman and Moore 1974. Opinion 88. Judicial Commission of the International Committee on Systematics of Prokaryotes. Int J Syst Evol Microbiol 2014;64:3578–3579. 130. Judicial Commission. Opinion 53: Rejection of the species name Mycobacterium marianum Penso 1953. Int J Syst Bacteriol 1978;28:334. 131. Margos G, Gofton A, Wibberg D, Dangel A, Marosevic D, etal. The genus Borrelia reloaded. PLoS One 2018;13:e0208432. 132. Tortoli E, Brown- Elliott BA, Chalmers JD, Cirillo DM, Daley CL, etal. Same meat, different gravy: ignore the new names of mycobacteria. Eur Respir J 2019;54:1900795. 133. On SLW, Miller WG, Biggs PJ, Cornelius AJ, Vandamme P. A critical rebuttal of the proposed division of the genus Arcobacter into six genera using comparative genomic, phylogenetic, and phenotypic criteria. Syst Appl Microbiol 2020;43:126108. 134. Schoch CL, Ciufo S, Domrachev M, Hotton CL, Kannan S, et al. NCBI taxonomy: a comprehensive update on curation, resources and tools. Database 2020;2020:baaa062. 135. Maiden MFJ, Cohee P, Tanner ACR. Proposal to conserve the adjectival form of the specific epithet in the reclassification of Bacteroides forsythus Tanner et al. 1986 to the genus Tannerella Sakamoto et al. 2002 as Tannerella forsythia corrig., gen. nov., comb. nov. Request for an Opinion. Int J Syst Evol Microbiol 2003;53:2111–2112. 136. Lambert DH, Loria R, Labeda DP, Saddler GS. Recommendation for the conservation of the name Streptomyces scabies. Request for an Opinion. Int J Syst Evol Microbiol 2007;57:2447–2448. 137. Oren A, Garrity GM, Schink B. Proposal to change the name Rhodoligotrophos Fukuda et al. 2012, 1947 to Rhodoligotrophus. Request for an Opinion. Int J Syst Evol Microbiol 2013;63:3545. 138. Oren A. Proposal to correct the generic name Flaviaesturariibacter Kang, Chun, Seo, Kim and Jahng 2015, 2212 to Flavaestuariibacter. Request for an Opinion. Int J Syst Evol Microbiol 2017;67:3686. 139. Oren A. Correction of the name Amycolatopsis albidoflavus to Amycolatopsis albidiflava corrig. Request for an Opinion. Int J Syst Evol Microbiol 2017;67:4284. 140. Euzéby JP, Tindall BJ. Necessary corrections to the Approved Lists of Bacterial Names according to Rule 40d (formerly Rule 46). Request for an Opinion. Int J Syst Evol Microbiol 2002;52:2321–2322. 141. Edwards J, Baque E, Tang J. Proposal to acknowledge Beijerinck as the original author of the species Pantoea agglomerans. Request for an Opinion. Int J Syst Evol Microbiol 2004;54:2437. 142. Holmes B, Farmer III JJ. Correction of the type strain of Aeromonas punctata (Zimmermann 1890) Snieszko 1957 and of A. punctata subsp. punctata from ATCC 15468T to NCMB 74T (=NCIMB 74T= ATCC 23309T). Int J Syst Evol Microbiol 2020;70:2155–2157. 143. Cato EP, Holdeman LV, Moore WEC. Designation of Eubacterium limosum (Eggerth) Prévot as the type species of Eubacterium. Request for an Opinion. Int J Syst Bacteriol 1981;31:209–210. 144. Sneath PHA. Status of nomenclatural types in the Approved Lists of Bacterial Names 1980. Request for an Opinion. Int J Syst Bacteriol 1982;32:459–460. 145. Mah RA, Kuhn DA. Transfer of the type species of the genus Methanococcus to the genus Methanosarcina, naming it Methanosarcina mazei (Barker 1936) comb. nov. et emend. and conservation of the genus Methanococcus (Approved Lists 1980) with Methanococcus vannielii (Approved Lists 1980) as the type species: Request for an Opinion. Int J Syst Bacteriol 1984;34:263–265. 146. Mah RA, Kuhn DA. Rejection of the type species of Methanosarcina methanica (Approved Lists 1980), conservation of the genus Methanosarcina with Methanosarcina barkeri (Approved Lists 1980) as the type species, and emendation of the genus Methanosarcina. Request for an Opinion. Int J Syst Bacteriol 1984;34:266–267. 147. Tindall BJ. What is the type species of the genus Paenibacillus? Request for an Opinion. Int J Syst Evol Microbiol 2000;50:939–940. 148. Neimark H, Peters W, Robinson BL, Stewart LB. Phylogenetic analysis and description of Eperythrozoon coccoides, proposal to transfer to the genus Mycoplasma as Mycoplasma coccoides comb. nov. and Request for an Opinion. Int J Syst Evol Microbiol 2005;55:1385–1391. 149. Young JM, Pennycook SR, Watson DRW. Proposal that Agrobacterium radiobacter has priority over Agrobacterium tumefaciens. Request for an Opinion. Int J Syst Evol Microbiol 2006;56:491–493. 150. Oren A, Garrity GM. The correct name of the type species of the genus Methanocorpusculum. Request for an Opinion. Int J Syst Evol Microbiol 2015;65:2013–2014. 151. Boden R, Oren A. Proposal to designate Methylothermus subterraneus Hirayama et al. 2011 as the type species of the genus Methylothermus. Request for an Opinion. Int J Syst Evol Microbiol 2017;67:3685. 152. Euzéby JP, Tindall BJ. Nomenclatural type of orders: corrections necessary according to Rules 15 and 21a of the Bacteriological Code (1990 Revision), and designation of appropriate nomenclatural types of classes and subclasses. Request for an Opinion. Int J Syst Evol Microbiol 2001;51:725–727. 153. Oren A. Proposal to designate the order Actinomycetales Buchanan 1917, 162 (Approved Lists 1980) as the nomenclatural type of the class Actinobacteria. Request for an Opinion. Int J Syst Evol Microbiol 2017;67:3687–3688. 154. Tao TS, Yue YY, Fang CX. Irregularities in the validation of the genus Thermodesulfobacterium and its species. Request for an Opinion. Int J Syst Bacteriol 1996;46:622. 155. Euzéby JP, Tindall BJ. A replacement name of the specific epithet aurantiaca in Micromonospora aurantiaca Sveshnikova et al. 1969 (Approved Lists 1980) and a proposal to treat the combination Micromonospora aurantiaca Sveshnikova et al. 1969 as a rejected name. Request for an Opinion. Int J Syst Evol Microbiol 2004;54:1905–1906. 156. Oren A, Parte A, Garrity GM. Implementation of Rule 8 of the International Code of Nomenclature of Prokaryotes for the renaming of classes. Request for an Opinion. Int J Syst Evol Microbiol 2016;66:4296–4298. 157. Judicial Commission. Opinion 57: Designation of Eubacterium limosum (Eggerth) Prévot 1938 as the type species of Eubacterium. Int J Syst Bacteriol 1983;33:434. 158. Judicial Commission. Opinion 62: Transfer of the type species of the genus Methanococcus to the genus Methanosarcina as Methanosarcina mazei (Barker 1936) comb. nov. et emend. Mah and Kuhn 1984 and conservation of the genus Methanococcus (Approved Lists, 1980) emend. Mah and Kuhn 1984 20 Arahal etal., Int. J. Syst. Evol. Microbiol. 2023;73:005782 with Methanococcus vannielii (Approved Lists, 1980) as the type species. Int J Syst Bacteriol 1986;36:491. 159. Judicial Commission. Valid publication of the genus name Thermodesulfobacterium and the species names Thermodesulfobacterium commune (Zeikus et al. 1983) and Thermodesulfobacterium thermophilum (ex Desulfovibrio thermophilus Rozanova and Khudyakova 1974). Opinion 71. Int J Syst Evol Microbiol 2003;53:927. 160. Judicial Commission. The type species of the genus Paenibacillus Ash et al. 1994 is Paenibacillus polymyxa. Opinion 77. Int J Syst Evol Microbiol 2005;55:513. 161. Judicial Commission. The nomenclatural types of the orders Acholeplasmatales, Halanaerobiales, Halobacteriales, Methanobacteriales, Methanococcales, Methanomicrobiales, Planctomycetales, Prochlorales, Sulfolobales, Thermococcales, Thermoproteales and Verrucomicrobiales are the genera Acholeplasma, Halanaerobium, Halobacterium, Methanobacterium, Methanococcus, Methanomicrobium, Planctomyces, Prochloron, Sulfolobus, Thermococcus, Thermoproteus and Verrucomicrobium, respectively. Opinion 79. Int J Syst Evol Microbiol 2005;55:517–518. 162. Judicial Commission. The adjectival form of the epithet in Tannerella forsythensis Sakamoto et al. 2002 is to be retained and the name is to be corrected to Tannerella forsythia Sakamoto et al. 2002. Opinion 85. Int J Syst Evol Microbiol 2008;58:1974. 163. Judicial Commission. Necessary corrections to the Approved Lists of Bacterial Names according to Rule 40d (formerly Rule 46). Opinion 86. Int J Syst Evol Microbiol 2008;58:1975. 164. Tindall BJ. The epithet aurantiaca in Micromonospora aurantiaca Sveshnikova et al. 1969 (Approved Lists 1980) is illegitimate and requires a replacement epithet. Opinion 89. Judicial Commission of the International Committee on Systematics of Prokaryotes. Int J Syst Evol Microbiol 2014;64:3580–3581. 165. Tindall BJ. The combination Enterobacter agglomerans is to be cited as Enterobacter agglomerans (Beijerinck 1888) Ewing and Fife 1972 and the combination Pantoea agglomerans is to be cited as Pantoea agglomerans (Beijerinck 1888) Gavini et al. 1989. Opinion 90. Judicial Commission of the International Committee on Systematics of Prokaryotes. Int J Syst Evol Microbiol 2014;64:3582–3583. 166. Tindall BJ. The Request for an Opinion that the current use of the genus name Mycoplasma be maintained and Mycoplasma coccoides be considered a legitimate name is denied. Opinion 92. Int J Syst Evol Microbiol 2014;64:3586–3587. 167. MacAdoo TO. Nomenclatural literacy. In: Goodfellow M and O’Donnell AG (eds). Handbook of New Bacterial Systematics. London: Academic Press; 1993. pp. 339–358. 168. Trüper HG. How to name a prokaryote? Etymological considerations, proposals and practical advice in prokaryote nomenclature. FEMS Microbiol Rev 1999;23:231–249. 169. Oren A, Vandamme P, Schink B. Notes on the use of Greek word roots in genus and species names of prokaryotes. Int J Syst Evol Microbiol 2016;66:2129–2140. 170. Oren A, Garrity GM. Proposal to modify the Note to Rule 61 of the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2016;66:3307–3309. 171. De Vos P, Trüper HG. Judicial Commission of the International Committee on Systematic Bacteriology IXth International (IUMS) Congress of Bacteriology and Applied Microbiology. Minutes of the meetings, 14, 15 and 18 August 1999, Sydney, Australia. Int J Syst Evol Microbiol 2000;50:2239–2244. 172. Judicial Commission. The genus name Sinorhizobium Chen et al. 1988 is a later synonym of Ensifer Casida 1982 and is not conserved over the latter genus name, and the species name ‘Sinorhizobium adhaerens’ is not validly published. Opinion 84. Int J Syst Evol Microbiol 2008;58:1973. 173. List Editor. Validation List no. 85. Validation of publication of new names and new combinations previously effectively published outside the IJSEM. Int J Syst Evol Microbiol 2002;52:685–690. 174. Euzéby JP. Validation List no. 111. List of new names and new combinations previously effectively, but not validly, published. Int J Syst Evol Microbiol 2006;56:2025–2027. 175. Oren A, Garrity GM. Validation List no. 159. List of new names and new combinations previously effectively, but not validly, published. Int J Syst Evol Microbiol 2014;64:2927–2929. 176. Oren A, Garrity GM. Validation List no. 163. List of new names and new combinations previously effectively, but not validly, published. Int J Syst Evol Microbiol 2015;65:1105–1111. 177. Oren A, Garrity GM. Validation List no. 184. List of new names and new combinations previously effectively, but not validly, published. Int J Syst Evol Microbiol 2018;68:3379–3393. 178. List Editor. Notification that new names and new combinations have appeared in volume 50, part 2, of the IJSEM. Int J Syst Evol Microbiol 2001;51:795–796. 179. Oren A, Garrity GM. Notification that new names of prokaryotes, new combinations and new taxonomic opinions have appeared in volume 65, part 7, of the IJSEM. Int J Syst Evol Microbiol 2015;65:3233–3234. 180. Oren A, Garrity GM. Notification that new names of prokaryotes, new combinations, and new taxonomic opinions have appeared in volume 69, part 5 of the IJSEM. Int J Syst Evol Microbiol 2019;69:2177–2178. 181. Oren A, Garrity GM. Notification that new names of prokaryotes, new combinations, and new taxonomic opinions have appeared in volume 70, part 2 of the IJSEM. Int J Syst Evol Microbiol 2020;70:2967–2971. 182. Oren A, Garrity GM. Notification that new names of prokaryotes, new combinations, and new taxonomic opinions have appeared in volume 70, part 11 of the IJSEM. Int J Syst Evol Microbiol 2021;71:4645. 183. Oren A, Garrity GM. Notification that new names of prokaryotes, new combinations, and new taxonomic opinions have appeared in volume 71, part 10 of the IJSEM. Int J Syst Evol Microbiol 2022;72:5165. 184. Sutcliffe IC, Dijkshoorn L, Whitman WB. Minutes of the International Committee on Systematics of Prokaryotes online discussion on the proposed use of gene sequences as type for naming of prokaryotes, and outcome of vote. Int J Syst Evol Microbiol 2020;70:4416–4417. 185. Oren A, Arahal DR, Rosselló-Móra R, Sutcliffe IC, Moore ERB. Emendation of Rules 5b, 8, 15 and 22 of the International Code of Nomenclature of Prokaryotes to include the rank of phylum. Int J Syst Evol Microbiol 2021;71:4851.