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Scientific Style and Format



The members of the Style Manual Committee have developed this new edition with the following aims in mind.

The recommendations presented in this manual are based as much as possible on standards for nomenclature and symbolization developed by authoritative bodies for scientific publication in English. Examples of such documents are the standards published by the National Information Standards Organization, the International Organization for Standardization, and the International Union of Pure and Applied Chemistry, as well as the style manuals of various specialty organizations, such as the American Chemical Society3 and the American Medical Association4 . As such, the manual represents a clearinghouse of sorts, collecting, organizing, and distributing information on standards for scientific presentation. Recognizing the expertise, authority, and influence of these various organizations, we have usually not attempted to arbitrate among them, and alternatives are presented at many points. Some scientific disciplines have deeply rooted conventions that are at odds with related conventions in other fields, and even within a single discipline such as genetics, there may be striking differences in conventions (see Chapter 21). In pointing out these differences, we hope that the manual will raise awareness of discrepancies in related conventions as a first step toward future harmonization of stylistic standards.

Where such discipline-specific standards are not available, well-established and widely used styles have been selected, as much as possible from such general style manuals as The Chicago Manual of Style2. Where we chose to depart from recommendations in these sources, our choices are explained. We encourage users to seek out existing standards of presentation, rather than developing new styles, especially if a particular problem is not covered here. This approach will contribute to the second aim of this manual, outlined below.

Eliminating differences in style for the same or similar situations in different disciplines would benefit authors, editors, publishers, readers, and librarians. With regard to general style, some characteristically British preferences are recommended in this manual because of the more convincing logic for their basis, for example, presenting any punctuation associated with closing quotation marks according to sense; see Section 10.2.4. Within various scientific disciplines, where standards are set by authoritative bodies such as the International Union of Pure and Applied Chemistry and the International Zoological Commission, we have pointed out differences but have not necessarily recommended one over another. We encourage those setting such standards to confer with their counterparts in other disciplines as they further develop their guidelines, and we encourage users to seek out and follow existing standards rather than contributing to the proliferation of variant styles. Some users of this manual and subject-area authorities may be reluctant to give up a few of their style preferences, but we ask them to consider the benefits of a truly common style, useful in the international world of science, not just in one nation or discipline.

The effort to simplify style rules where possible is based in part on the wish to bring about convergence in style for the advantages of a more uniform style throughout science. Another reason is the value of reducing the number of style decisions required. Examples are eliminating the possessive form for eponymic terms (see Section 6.5.6) and using numerals for almost all numbers modifying countable units, not just for numbers above 9 or 10 (see Section 12.1.2).

Scientific publication is characterized by myriad formats for bibliographic references. The recommendations on reference format presented in this manual emphasize the information that is required to ensure retrievability of the cited documents. We hope that by specifying these necessary elements and illustrating their virtually identical use in 3 referencing systems (citation-sequence, also known as "Vancouver style"; name-year, also known as "Harvard style"; and citation-name), we can encourage convergence in reference style. At the same time, we have attempted to provide as much detail as users will need to properly reference their source documents, using established bibliographic standards as the basis for recommendations. The chapter on reference style now includes detailed guidance on citing various types of electronic documents, which are now so prevalent. Punctuation is an important aspect of established bibliographic standards, and each mark of punctuation has a specific meaning in the context of bibliographic references. As such, punctuation practices within the reference section of a document may differ from those in the main text.

Some recommendations are aimed at reducing work at the keyboard. Examples are the preferences for avoiding unnecessary punctuation (see Section and using a hyphen instead of an en dash for page ranges and other components of end references (see Section


The text is divided into chapters grouped in 4 parts. Part 1 provides an overview of important issues related to scientific publication, including editorial practices and copyright. Part 2 covers conventions widely applied in both general and scientific scholarly publishing. Part 3 covers details of style mainly applicable in the sciences. Part 4 recommends formats applicable in scientific journals and books, including formats for bibliographic citations and references, and covers the technical aspects of publishing.

Within chapters, the section numbering is hierarchical, and section numbers are linked to headings.

References and their citations are presented in the citation-name format. This choice was based on certain advantages of that system (see Section 29.2.3), in particular, avoiding the difficulties associated with citing electronic documents by author name and date of publication, since in many such documents this information is not clearly identified. Authoritative online resources, where such are available, are provided in chapter reference lists.

In this seventh edition of the manual, users will find a new section covering the fundamentals of scientific publication. Chapter 1, "Elements of a Scientific Publication", outlines briefly the essential components of scientific articles, books, and other types of publications, stressing the need for coherent structure. Chapter 2, "Publication Policies and Practices", covers the responsibilities of authors, editors, and peer reviewers related to a variety of ethical concerns and situations, including conflict of interest, peer review, data falsification and plagiarism, redundant publication, and authorship disputes. Based primarily on the editorial policy statements of the Council of Science Editors, the chapter was created in response to continuing requests for this type of information. Chapter 3, "The Basics of Copyright", covers copyright requirements and practices in the United States, Canada, Australia, New Zealand, and the United Kingdom. It is included for the benefit of users of the manual who might not be aware of this potentially thorny area, especially authors and editors who are not working in a dedicated publishing milieu. The chapter is also intended as a way to emphasize that copyright requirements continue to hold even in this age of electronic documents, which are easily copied and transmitted.

Within Part 2 of the manual, "General Style Conventions", Chapter 12 "Numbers, Units, Mathematical Expressions, and Statistics", presents a modified version of the number style that was recommended in the sixth edition1. In this updated CSE number style, most cardinal numbers (except for zero and one) are usually presented as numerals, and ordinal numbers from "first" through "ninth" are usually presented as words.

The content of Part 3 of the manual, "Special Scientific Conventions", has been updated throughout to reflect changes in recommendations from authoritative bodies. Several specific changes are highlighted as follows.

Chapter 17, "Chemical Formulas and Structures", has been augmented by the inclusion of structural formulas.

The expanded chapter "Genes, Chromosomes, and Related Molecules" (Chapter 21) includes summaries of all published genetic nomenclature rules that could be identified during preparation of the chapter. To our knowledge, these rules have not previously been gathered in one place. Genetic nomenclature rules are provided for viruses, bacteria, yeasts, fungi, protists, plants (cereals, crucifers, legumes, and others), nonhuman animals (fish, avian species, domestic animals, rodents, transgenic animals), and humans.

Chapter 22, "Taxonomy and Nomenclature" consolidates nomenclatural recommendations for plants, fungi, algae, lichens, animals, bacteria, and viruses in a single chapter. This organization emphasizes both the aspects of nomenclature that are common to all types of organisms and the aspects that differ among the various nomenclatural codes. The chapter content reflects revisions to the International Code of Botanical Nomenclature, the International Code of Zoological Nomenclature, and Virus Taxonomy: Classification and Nomenclature of Viruses that have been published since the previous edition of the manual appeared.

Similarly, Chapter 23, "Structure and Function of Organisms", brings together stylistic recommendations related to normal structure and function. Chapter 24, "Disease Names", discusses the nomenclature of diseases of animals and plants, but does not address the physiological or clinical aspects of diseases or their treatment.

Chapter 25, "The Earth", has been expanded to include new sections on water (covering the physical properties of seawater, currents, and tides) and air (covering scales of motion, winds, and satellites).

Chapter 26, "Astronomical Objects and Time Systems", summarizes the 5 astronomical time systems now in use, reflecting several changes in accepted practice in recent years. The manual no longer includes a chapter dedicated to human history and society, but some aspects of that topic, specifically those related to time and the names of ethnic groups, have been incorporated into the relevant chapters of Part 2, "General Style Conventions".

In Part 4, "Technical Elements of Publications", the expanded chapter on references includes comprehensive guidance on all aspects of citing print and electronic resources. The recommendations in this chapter conform to the bibliographic recommendations of the National Information Standards Organization. All examples are taken from the published literature, to illustrate how the recommendations should be put into practice. Also in Part 4, the chapters on journals and books have been enhanced to provide advice pertinent to both electronic and print publication.

Monitoring the scientific literature for documents establishing or recommending new nomenclature, notations, or formats is a huge task. We urge scientific societies, committees, working groups, individual scientists, and others to send to the Council of Science Editors both formal and informal documents with recommendations on nomenclature, symbols, and style, whether they are new or simply not represented in this edition. The committee responsible for the style manual will review suggestions in consultation with subject experts and decide on the recommendations to be represented in future editions. Send suggestions to the Council of Science Editors, Attention: Style Manual, 12100 Sunset Hills Road, Suite 130, Reston VA 20190; fax 703-435-4390; ( ).



1. CBE Style Manual Subcommittee. Number style recommended in Scientific Style and Format. CBE Views. 1998;21(1):14-16.
2. The Chicago manual of style: the essential guide for writers, editors, and publishers. 15th ed. Chicago (IL): University of Chicago Press; 2003.
3. Dodd JS, editor. The ACS style guide: a manual for authors and editors. 2nd ed. Washington (DC): American Chemical Society; 1997.
4. Iverson C, Flanagin A, Fontanarosa PB, Glass RM, Glitman P, Lantz JC, Meyer HS, Smith JM, Winker MA, Young RK. American Medical Association manual of style: a guide for authors and editors. 9th ed. Baltimore (MD): Williams & Wilkins; 1997.

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