AMA Manual of Style - Stacy L. Christiansen, Cheryl Iverson 2020


Opening any new book can be cause for excitement. But for an editor, opening a new edition of a style manual has an added frisson. What is new? Have gaps been filled? Have policies that may have seemed outdated or stodgy been freshened?

These questions can only be answered by frequent use, but to provide a quick overview here is a short list of what you will find in this 11th edition of the AMA Manual of Style.

■The hyphen has been removed from email, although it is retained for other e-combinations (eg, e-cigarette).

■Both internet and website are lowercased (and the former Web site is now one word).

■The mandate for a single corresponding author has been relaxed. Two corresponding authors may be listed if justified, with one author designated as the primary point of contact responsible for all communication about the manuscript and article. This person will be listed first in the Corresponding Author section of the published article.

■Because it has become increasingly common for authors to request “co—first authorship” or “co—senior authorship,” such designations will now be allowed, but one person’s name will need to go first in the byline.

■The death dagger in the byline for a deceased author has been discontinued. If it is desired to note the death of an author, this may be done in the Acknowledgment section.

■Location of the publisher for books and reports is no longer required in references.

■Location of the manufacturer of drugs and equipment and devices is no longer required in text.

■A DOI (digital object identifier) should be included for journal references if available.

■Because the ability to easily and accurately copy and paste DOIs is important, a period should not be included after the DOI; the risk of the period becoming a part of the DOI itself is too great and could create problems with linking.

■When a URL is included for references, it should be preceded by the date the reference was published and/or last updated and accessed. This would make the URL the last item in the reference citation and, as with DOIs, it should not be followed by a period to avoid confusion with linking.

■Guidance on citing preprints, databases, data repositories, podcasts, apps and interactive games, and popular social media (eg, Facebook, blogs, YouTube, and Twitter) has been added to the References chapter.

■In tables and figures, sentence-style capitalization will be used in all elements except the title (eg, axis labels, column headings). This makes long phrases easier to read.

■In the chapter on Tables, Figures, and Multimedia, new examples of the following types of figures have been added: hybrid graph (2 techniques are overlaid), flowchart for a clinical trial in which participants were allocated vs randomized, funnel plot, genetic heat map, network map, gel electrophoresis images, magnetic resonance images, radiographs, ultrasonographic images. Color has been added throughout the chapter where appropriate.

■Guidance on publishing statements about data sharing has been added.

■Additional detail about public access, open access, article processing charges (APCs), open access journals, and updates on copyright, licensing, and Creative Commons (CC) licenses have been added.

■A new correction option allows retraction and replacement of an article in cases in which pervasive, but inadvertent, error(s) resulted in incorrect data throughout an article and a significant change in the findings, yet the underlying science is still reliable and important.

■Hyphens are not used in some combinations of words that are commonly read together; for example, open access journals, health care system.

■The singular they is permitted when rewriting a sentence as plural would be awkward or unclear.

■The terms first world/third world and developed/developing are not recommended as descriptors when comparing countries or regions.

■Labeling people with their socioeconomic status (eg, the poor or the unemployed) should be avoided in favor of language such as individuals with low income or no income.

■New terms related to addiction have been added: avoid addict, alcoholic; favor person with opiate addiction, a person with alcohol use disorder.

■Other new terms have been added to Correct and Preferred Usage, with clarification on use or when to avoid use, eg, nauseous, nauseated; foreign-born; elicit, illicit, solicit; alternative, alternate; cerebrovascular accident, stroke, stroke syndrome; life expectancy, life span; substance use, substance abuse.

■A new section on spelling and spacing variations has been added to Correct and Preferred Usage (eg, ante mortem/antemortem, post mortem/postmortem, heart beat/heartbeat). And yes, we still prefer health care over either healthcare or health-care.

■Some standards on grammar in social media have been added to the Grammar chapter to ensure clarity.

■In author bylines, all fellowship designations (eg, FRCP, FRCPC) and honorary degrees will no longer be included. Degrees below the master’s level (eg, BS, BA) will only be included if they are the highest degree held.

■The Manuscript Preparation chapter adds guidance on the inclusion of figures or tables in the structured abstract, ancillary educational and promotional material (eg, audio, video, quizzes), and online-only supplements (text, tables, or figures).

■Use of aliases/nicknames for genes and proteins is strongly discouraged, although it may be necessary to dual report for aliases well-entrenched in use: ERBB2 (previously HER2/neu).

■Following the recommendation of the Human Genome Variation Society, the terms mutation and polymorphism should be avoided, preferring instead the terms sequence variant, sequence variation, alteration, or allelic variant. Related to this recommendation, SNV (single-nucleotide variation) is now preferred to SNP (single-nucleotide polymorphism). To aid in readers’ understanding during this transition, at first mention SNV may be used, with SNP in parentheses: SNV (formerly SNP).

■The difference between genome and genome assembly is elucidated, as well as the importance of the GenBank identifier.

■In the discussion of human chromosomes, the movement from the study of structural variation from the perspective of direct visualization of bands, using staining techniques, to sophisticated fluorescent technologies to probe for structural variations is emphasized.

■Material on plant genetics (specifically corn, rice, and soybeans) has been added.

■Guidance on Salmonella nomenclature has been updated. Traditional binomial species designations are no longer applied to serotypes; now Salmonella Typhi, not Salmonella typhi.

■Currencies have been updated, including African denominations such as the Ethiopian birr, the Ghanaian cedi, the Malawian kwacha, the Nigerian naira, the Ugandan shilling, and the Zimbabwe dollar.

■Per SI convention, we no longer close up degree symbols in temperature with degrees Celsius and degrees Fahrenheit, but use a space after the number: a temperature of 37.5 °C (not 37.5°C).

■The SI conversion table has been updated, and it no longer includes laboratory reference values because of differences among laboratories worldwide.

■The chapter on indexing has been dropped.

■The abbreviation CI (for confidence interval) will no longer require expansion.

■Many new terms have been added to the Glossary of Publishing Terms, eg, cloud, Creative Commons, open access, hybrid open access, IP (International Protocol) address, JATS (Journal Article Tag Suite), JSON (JavaScript Object Notation), LaTeX, NISO (National Information Standards Organization), Unicode.

■A new section on Guidelines (eg, COPE, EQUATOR Network, ICMJE, WAME) has been added to the Resources chapter.

■A list of specific study types and definitions, with links to reporting guidelines, has been added to the chapter on article types.

■There is an expanded definition of bias, with many examples of types of bias, in the Study Design and Statistics chapter.

■The distinction between multivariable and multivariate is clarified.

■In displaying forms of statistical analysis, terms should not be shown as subscripts (eg, Pinteraction<.001). Instead, use P <.001 for interaction.

■The Mathematical Composition chapter includes more examples of complicated forms of fences in equations.

■Use a thin space (a space usually ¹/5 or ¹/6 the width of an em dash: Unicode value is 2009) before and after mathematical symbols when they are used as verbs, conjunctions, or operators: ±. =, <, >, ≥, ≤, +, −, ≈.

■XML (discussion and tagging examples) rules for naming and defining parts of a document and their relationship to each other has been added, as well as a discussion of JATS tagging.

■The basic workflow of a manuscript has been updated to show single-source workflow. In this process, content remains in the original document format (eg, Word) and is stored with the XML file and related content (eg, supplemental files, multimedia). Because XML is the basis of this workflow and content, any changes required (before, during, or even after publication) must be made in the source document and new XML generated.

There may be long stretches between editions of a style manual, but an online version of the manual provides the opportunity to not only correct errors but also to provide updates and new policies. These are published on the Updates page of the online manual, which is freely available to everyone: Regular communication via Twitter (@AMAManual) and posts to our blog ( provide additional enhancements.

We have continued to work with a committee, dividing the work at the outset, doing independent research and writing, obtaining critiques from outside peer reviewers, and providing critiques on all of each other’s material. Often, several cycles of writing, reviewing, and rewriting were necessary. As with the last edition, each chapter is attributed to a principal author. Others who added strength to the work are listed in the Acknowledgments section. And special thanks is due to Laura King, MA, MFA, ELS, who copyedited the entire book.

We welcome your comments on the manual, whether they are suggestions for improvements, alerts to possible corrections, or questions. Write to

Cheryl Iverson, MA

Stacy L. Christiansen, MA

Co-chairs, AMA Manual of Style Committee