Global Editions

House style guide


Abbreviations: On first use, any terms later abbreviated should be spelled out, with abbreviations appended in parentheses (exceptions noted below). Do not use abbreviation initially and append definition, unless (1) abbreviation is used again in the same sentence, or (2) abbreviation is part of a quote. See also Companies.

Abbreviations admissible on first use:





Acronyms: Acronyms (for projects or organizations) of more than six letters are written in sentence case. See also Companies and Proprietary projects and products. For common expressions: Acronyms of common expressions (O.D. for overdose, M.O. for modus operandi, etc.) are capitalized with periods, except where otherwise noted (e.g., a.k.a.).

Airline flight numbers: Capitalize “flight,” as in Flight 702.

a.k.a.: Lowercase, with periods.

Ampersands: No spaces when used in acronyms, as in AT&T. Keep the ampersand in company names when warranted, e.g., Procter & Gamble, Johnson & Johnson.

Antenna, plural: “antennas” for the things that send and receive transmissions, “antennae” for the things insects have.

Baby Boomer: Uppercase.

because: Precede “because” with a comma when the subordinate clause is nonrestrictive. (“She didn’t wear her raincoat, because it was too warm.”)

Big Bang: Uppercase.

Binary: Use “1” and “0”, in italics, to designate binary units of information. So: “The 1s and 0s of a digital file are stored as switch positions in a computer.”

BlackBerrys: Uppercase “Berry,” form plural by adding s.

brass rat: Lowercase.

Caliber: Hyphenate: “.22-caliber pistol,” etc.

Callouts: A passage from an article can be paraphrased for a callout, but a quote from the story that appears in quotation marks as a callout has to match the original quote.

Caltech: Written solid, lowercase “tech.” Acceptable on first reference for the California Institute of Technology.

Cambridge University: Incorrect. “University of Cambridge” on first use. (See also Oxford.)

Canada: Canadian cities are identified by province only (e.g., Kitchener, Ontario).

the Cape: So written when referring to Cape Cod.

catch-22: Lowercase (except when referring to novel).

Chemical compounds: On second use, names of organic compounds may be abbreviated according to convention (“apolipoprotein E” to “apoE”), and other long, unwieldy chemical names may be abbreviated to formulae, if they are spelled out on first use and their abbreviations appended in parentheses. Exceptions are abbreviations of organic-compound names so common as to be more recognizable than their referents (DNA, THC, etc.). Spell out names of simple compounds (“carbon dioxide,” not “CO2”). No hyphens in names of compounds used as adjectives (“carbon dioxide emissions”).

Cities: The following city names are not followed by state names—except in tables, if necessary for consistency:

Las Vegas
Oklahoma City
San Antonio

Los Angeles
San Diego

San Francisco


St. Louis

New York
Salt Lake City

Clinical trials: Write “phase I”, “phase II”, etc., lowercase, with Roman numerals.

Coined phrases: Use lowercase. On second use, coinages may be abbreviated to common acronyms (“single-nucleotide polymorphisms” to “SNPs”) if they are spelled out on first use and their abbreviations appended in parentheses. Quotation marks: Roughly, when the description of a process or tool is metaphorical (“data mining”), enclose it in quotation marks on first use; when it’s literal (hybrid brain-machine interfaces), don’t. Exceptions are terms used with such frequency in our pages (e.g., data mining, big data) that their metaphorical meanings have become transparent.

Cold War: Uppercase.

Colloquium: Plural “colloquia.”

Colons: When a colon is used as internal sentence punctuation, the first word following is lowercase (unless, of course, it’s a proper noun). When the colon introduces several consecutive sentences, the next word following is uppercase. E.g., “Here’s how the process works: Large wafers are grown from silicon crystals. Chips are etched on the wafers. Metal leads are wired to the silicon electronics.”)

Colons should not precede quoted matter introduced by standard “discourse” verbs. E.g., the following sentences are incorrect: “As one researcher confided: ‘It’s costing us $150,000 a day’”; “Says Peterson: ‘A breakthrough could be around the corner.’” Colons should precede quoted matter not introduced by standard discourse verbs. E.g., “Miller is realistic about his chances: ‘We’re one of a hundred companies working on this drug.’”

Commas: We use the serial comma.

Companies: Do not use Inc., Co., or Corp. in company names. Do not use their foreign equivalents (Ltd., AG, KK, PLC, etc.), nor generic terms like Industries, Manufacturing, etc. On first use, however, do use specific industry terms, like Motor, Telephone, Electronics, etc.

The following company names may be abbreviated on first use:




The following company names may be abbreviated on second use:

Advanced Micro Devices

British Telecommunications

European Aeronautic Defense and Space

General Electric


Hippon Telegraph and Telephone

Texas Instruments

Do not spell company names all-uppercase or all-lowercase, even if they are so trademarked. Where company names are partially capitalized, capitalize only the first letter in the capitalized series. So deCODE Genetics becomes deCode Genetics. Capitalize lowercased company names at the start of sentences. E.g. “He went to work for eBay” but “EBay hired him.”

Company locations: It is not a necessary to say where a company is headquartered. If you do give the location, it is not necessary to do so on first reference to the company.

cox-2: lowercase, hyphen, numeral

to articles in same issue. (see “Article Title,” page ##)
to articles in other issues. (see “Article Title,” Month/Month Year)

When the title of a cross-referenced article takes terminal punctuation, do not use a comma to separate it from the issue date or page number.

CT scan: not CAT scan.

“Cyber” prefix: close up in most uses, as in cyberterrorism, cyberspace. But cyber espionage, two words.

D.C. (District of Columbia): With periods.

Decades: Write out decades (1840s, 1970s), except when consecutive decades are listed consecutively. (So: “The American cult of youth flowered only in the 1960s and ’70s.” But “Enormous productivity growth characterized the 1950s and 1990s.”)

Deks: These should be complete sentences, both online and in print.

Departments: When referring to magazine departments by name (Demo, Reviews), capitalize but use neither quotes nor italics.

Depression: Cap when referring to the Great Depression.

Diabetes: Types of diabetes are written with the word “type” lowercase and numerals, e.g., “New gene therapies that target type 2 diabetes have entered human trials.”

Diareses: The dieresis is used over the second of two repeated vowels to indicate that they are pronounced as separate syllables instead of forming a single sound: coöperate, reëlect, microörganism, etc. In the case of consecutive i’s, a hyphen is preferable: anti-inflammatory, anti-intellectual. Letters with diereses can be found on the Symbol palette under the Insert menu in Word and the Glyph palette in InCopy.

Diseases: When diseases are known by the names of their discoverers, use the word “disease” on first use (“Parkinson’s disease”). Possessive form of discoverer’s name may be used thereafter (“Parkinson’s”). Use most common form of disease name, e.g., “Huntington’s disease,” not “Huntington’s chorea.” Exception: “Down syndrome” is acceptable because it has become common usage.

“Disk” vs. “Disc”: Disks are found inside disk drives and are rarely seen by nonprofessionals; discs are shiny and round and held by their edges.

Domain names: Top-level domain names (.com, .net, .edu, etc.) are spelled Roman without quotes when referring to domains qua domains, with quotes when referring to names qua names. E.g., “All Internet addresses with ‘.com’ in the title belong to the .com top-level domain.” The same holds for the domain names of individual sites. E.g., “Acme widgets, which is currently found at, is considering investing $50,000 to purchase the name ‘’ from a domain-name speculator.”

e-: Lowercase, hyphen in running text (e-mail, e-retail, e-book, etc.), except capitalized at beginning of sentence.

“Earth”: Capitalize “Earth” only when referring to the earth as an astronomical object. E.g., “The diameter of Earth’s orbit is approximately twice Mercury’s.” In such cases, do not use the definite article.

Educational degrees: No periods in abbreviations.

Ellipses: Use spaces around before and after. Use additional punctuation on either side of ellipsis where dictated by syntax of abridged quote. Do not use ellipses at beginning of quoted phrase.

Ethernet: Uppercase.

flash memory: Lowercase.

Federal agencies: Write out on first use (do not append abbreviations). Precede with “U.S.”, unless federal designation is part of title. Abbreviations thereafter.

Fractions: hyphenate fractions. Fractional compounds: hyphenate fractional compounds (e.g., “half-century,” “half-dozen”).

Gene names: Italicize, but the names of their protein products are roman. For primates (including humans), use all caps; mouse and other mammal genes get initial caps, and other species are all-lowercase.

Genus and species names: Italicize. Genus capitalized, species lowercase. On first use, spell out genus. Thereafter it may be abbreviated. Exceptions are names of common bacteria more familiar in their abbreviated forms (E. coli).

Global Positioning System: Capitalized when spelled out, but “GPS” is admissible on first use.

Green Revolution: Capitalized.

Gulf War: Refers to the 1990 U.S. military action in Kuwait and Iraq. Capitalized.

Headline capitalization: Capitalize all nouns, pronouns, adverbs, and verbs. (“Is,” “are,” “be,” etc. are verbs. Things like the “up” in “stand up” and the “out” in “take out” are part of the verb.) Some copy editors would lowercase all prepositions, but capitalize those longer than four letters, e.g.; between.

Human Genome Project: Capitalized.

Hyphens: In titles: When hyphenated compounds occur in titles, capitalize all components separately. So: “The Small-Business Deluge.”

In compound nouns: Normally, compounds used as nouns are not hyphenated. “He drives a sports car,” “in real time,” etc.

In compound modifiers: Some compounds are always hyphenated when they modify a noun. These include those joining a number to a noun or adjective: three-mile hike, five-pointed star, 40-year-old virgin. So are those ending with a participle or similar: man-eating shark, moth-eaten sweater, well-armed militia. Compound modifiers with long, longer, and longest are hyphenated (“long-term loan”—but “in the long term”). Those with more, most, less, and least usually are not.

Other compound modifiers are never hyphenated. These include chemical compounds, proper nouns (“New York office”), foreign phrases (including “in vitro” and “in vivo”), and those consisting of an –ly adverb plus an adjective (“beautifully decorated house”). Sums of money using combinations of figures and words do not use hyphens (“$150 million loan”), but fully spelled out versions do (“two-million-dollar loan”).

For noun phrases used adjectivally before another noun, there can be no rule that covers all cases. The purpose of the hyphen is to show at a glance which words go together—“small-business loans” are loans for small businesses, but “small business loans” could conceivably be loans of small amounts. If the phrase is extremely common, like “civil rights” or “high school,” there is probably no need for a hyphen to turn it into an adjective unless confusion could result (“banana bread pudding” is not the same as “banana-bread pudding”). But if confusion really could result, you may not want to make understanding hinge on a hyphen.

In general, we tend to err on the side of hyphenating.

Compounds of more than two words: If one of the words used in a compound is itself a compound, generally hyphenate the whole thing: “the team experimented with other lithium-ion-detecting substrates.” Use an en-dash to join it to the other word if regular hyphenation could cause confusion or if the original compound is capitalized, italicized, etc.: “nickel¬–metal hydride battery,” “The surgeries are part of a U.S. Food and Drug Administration–approved study.” (But “a study approved by the U.S. Food and Drug Administration” would be better.)

Prefixes: Words containing the following prefixes are written solid, except, sometimes, when the word modified begins with the prefix’s concluding letter (anti-inflammatory, but preëmpt) or when the word modified is capitalized (anti-Semitic): anti, co, multi, non, pre, re, super, un, under

Following are the house spellings of common compounds:

health-care (adj.)
real-time (adj.)

home page

scroll bar

ink-jet (adj.)
skunk works

dot com (n.)
slide show

dot-com (adj.)
spinoff (n.)

number one (adj.)
spin off (v.)

half a dozen
offline (Internet context)
sport-utility vehicle

online (Internet context)
startup (n.)

test bed

hardwire, hardwired

health care (n.)
race car


Including: A lot of writers to like to follow this word with a prepositional phrase instead of a noun or noun phrase. Don’t do that. (Example: “He has traveled widely, including in Asia and Europe.” Better: “He has traveled in many parts of the world, including Asia and Europe.”)

Industrial Revolution: Capitalized.

Internet, Net: Capitalized. No apostrophe before “Net.”

Iraq War: Capitalized. The 1990 U.S. military action in Iraq is the Gulf War, also capitalized.

“Laboratory”: If part of a proper name (e.g., MIT’s Artificial Intelligence Laboratory), write out on first use. May be abbreviated to “Lab” thereafter.

“maker” suffix: Do not hyphenate. Write solid only if listed in dictionary. (So “automaker,” “dressmaker,” but “chip maker,” “enzyme maker.”)

Micrometer: not micron.

“mid” prefix: When applied to years and centuries, mid is always hyphenated.

Materials science: Rather than “material science.”

Military branches: Uppercase Army, Navy, Marines for the U.S. services, despite what the Chicago style guide says.

MIT awards: The full name of, e.g., the Lobdell award is the Harold E. Lobdell Award, in which case “award” is capitalized. Otherwise, “Lobdell award” is shorthand, and “award” is lowercase.

MIT names and numbers: In the MIT News, courses are no longer designated by Roman numerals. MIT ended that practice.

Months: Write out the names of months.

Moore’s Law: “Law” capitalized.

Mouse (computer): Plural “mouses.”

Museum exhibits: Names of museum exhibits are capitalized, not italicized.

Newspapers/Magazines: “the” in a title is lowercase and roman, but a place name in a title is italicized (e.g., “the New York Times”). An exception can be made if “The” does not come before a place name, e.g., The New Republic}

“Nano” prefix: For coinages, use open form (nano economy). For commonly used industry terms, write solid (nanostructures, nanobots, nanocomputers, nanoscale, nanolithography, nanofabrication, nanoscopic, and, of course, nanometer).

Nobel Prizes: Capitalize “Nobel” and “Prize” but lowercase subject areas. (This has the added advantage of allowing us to say just “medicine” instead of “physiology or medicine.”

Northeast Corridor: Uppercase.

Numbers: 10 and higher use numerals. Spell out nine and lower through all mensural uses (two-meter-tall six-year-old) and modifications (second, sixth, eight dollars). Three exceptions: Decimals (9.2 million); percentages (9 percent); round numbers used as approximations (“tens of thousands of transistors are squeezed onto a single chip,” or “roughly a tenth of all gallium arsenide chips fail in production”). See also Binary. Ordinal compounds: Hyphenate ordinal compounds (“third-largest petroleum exporter,” etc.).

Numerical ranges: Use “to,” where syntactically logical, instead of hyphens.

Oxford University: “University of Oxford” on first use.

Page references: The word “page” should be spelled out when used in the text proper (e.g., “On page 27 of our cover story package, we provide an overview…”).

Patent Office: Full name: U.S. Patent and Trademark Office. “U.S. Patent Office” capitalized; references to “the patent office” lowercase.

percent: Write out.

periods: Put one space after a period, not two.

Political parties: Identify politicians in normal language. “John McCain, a Republican from Arizona.” Don’t use common abbreviations like (R-Arizona) .

Possessives: Plural nouns ending in “s” take apostrophe only. Otherwise, everything takes apostrophe ess except proper names ending with the “eeze” sound spelled “es” (Xerxes, Maimonides, Mercedes). The “plural nouns” rule applies to plurals that are contained in proper names, e.g., Lucent Technologies (Lucent Technologies’ Bell Labs).

Proprietary projects and products: Caps, no quotes. We do not indulge manufacturers who wish their products’ names to be rendered all in caps. For partial capitalizations see Companies.

Qaddafi, Muammar

QWERTY: Written with block caps.

Résumé: note accents

Reportedly: Try to avoid this word, which does the reader a disservice because it merely says someone reported something. Instead give the reader a sense of who reported it. Or confirm it yourself.

Self-reference: Do not use first-person plural. Use “MIT Technology Review.” The name of the publication is italicized, but the company’s name is not. If there is a document in which we would have to shift repeatedly between italics and roman, leave the name out of italics throughout.

September 11: or 9/11. Not 9-11.

“show stopper” vs. “showstopper”: “Showstopper” is a flattering term. It means a performance so spectacular that the ensuing applause halts the show. Technologists tend to use it to mean “something that will halt the development of a product.” In the second sense, it should be written open. (It should not be used at all except in direct quotes.)

Smartphone: one word. But “cell phone” remains two words.

Software: Do not italicize names of software packages (including games). When software is designated by version number, “version” is lowercase, and no comma separates it from the program name (Napster version 4.1).

Spelling: House spellings of some words with multiple accepted spellings:


sync (as in “in sync”) but synched, synching

traveled, traveling

dialogue (in the sense of conversation, but “dialog box”)





skeptic, skeptical

States: Spell out state names. Do not use two-letter postal abbreviations.

The States: Capitalize “States” when referring to the United States as “the States.”

Street Names: Spell out “Street,” “Avenue,” “Boulevard,” etc., when they appear as part of a proper noun in running text. When used as plurals after two proper nouns, capitalize “Streets,” “Avenues,” “Boulevards,” etc., if they would be capitalized as singulars.

Synching: This is the preferred way of spelling the shorthand for “synchronizing.” Not “syncing.”

Telecommunications industry: Telecom industry is okay on first mention.

Television networks: Acronyms of televisions networks—broadcast or cable—may be used on first mention.

Temperatures: All temperatures in Celsius. Use degree symbol (º) and capital C (30 ºC). Space before but not after the degree sign.

Third World: Capitalize, but use sparingly.

Three-dimensional vs. 3-D: Note hyphen.

Times of day: Include minutes (i.e., 9:00, not 9). A.M. and P.M., SMALL CAPS with periods. Normal caps acceptable online.

Titles: Italicize titles of Web magazines like Slate and Salon, but not blogs. Personal titles: Personal titles should be capitalized only when they are part of a name. So, for instance, the word “president” should be lowercase in the sentence “The employee-of-the-month award is named for MIT president Charles M. Vest,” which is syntactically equivalent to “The award is named for MIT’s current president, Charles M. Vest.” The word “president” should be capitalized in the sentences “The award was named for President Vest,” or “The award was named for President Charles M. Vest” because his title is president, not MIT president.

T-shirt: Not tee shirt.

Units of measurement: spell out units of measurement (kilobytes, megahertz, etc.). Measurements generally in metric—except in direct quotes, or where context renders metric measurement bizarre (e.g., “We had seats on the 45-and-a-half-meter line” instead of “50-yard line”).

University names: Full name and word “University” in first use (the Pennsylvania State University, Duke University); name or common abbreviation thereafter (Penn State, Duke). Exceptions: “MIT,” “Caltech” admissible on first use. Campus names: Designate campuses according to the traditions of the university in question. So “University of California, Berkeley,” but “University of Wisconsin-Madison” and “University of Texas at Austin.”

URLs: Use “www.”, but do not use “http://”.

User: Be careful not to overuse this term for a customer or member of a Web service. For one thing, participation in online services often entails a deeper degree of involvement than mere “use.” And repetition of “user” tends to lead to awkward constructions such as “Facebook is gaining many developing-world users, who use the site very differently.” Try to substitute “members,” “customers” or “people.”

Vietnam, Viet Cong: so written.

War: Spell out names of world wars (no WWI, WWII); use Roman numerals for numbers (World War II, not World War Two).

Web: Capitalized. World Wide Web (capitalized, no hyphens). Words in common use with the “web” prefix and written solid, however, should be written lowercase (“website,” “webmaster,” “webcam”). For coinages that are not written solid, preserve capitalizations (“hordes of these little Web fiends are running wild on ostensibly serious bulletin boards.”)

Word Division: Quick summary of Chicago’s word division rules

1) follow Webster for breakpoints
2) syllables with silent “e” (like past participles) are not syllables; nor are syllables with liquid “l” (“-ble,” “-ple,” etc.)
3) “-cial,” “-ceous,” “-geous,” etc., are monosyllables: never divided
4) divide after vowel, unless followed by two consonants and another vowel; then divide after first consonant
5) do not break before vowels that alone form syllables—except for “ible” and “able,” etc., which are construed as monosyllables
6) no one-letter divisions
7) two-letter divisions permissible at end of line, but not at beginning
8) divide compound words at hyphen
9) divide words with prefix at prefix
10) Divide gerunds before “ing”—except for words with doubled consonants or whose roots contain liquid “l.”
11) Try not to divide names

x-ray: Lowercase, hyphenated, in all uses.

Years: Write out years (in numerals). When stipulating eras, use “B.C.E.” (rather than “B.C.”), with periods, for dates before the year 0, “C.E.” (rather than “A.D.”), SMALL CAPS with periods, for dates thereafter.


e-: Words introduced by e- prefix should be capitalized when they appear in titles (e.g., “Revolution in E-Book Technology!”).

Illustration credits: Single credits: Original art or photo, name only; graphic, art, or photo provided by story source or some other unpaid provider, introduce with “courtesy of.” Multiple credits: If multiple credits are given for illustrations in the same medium (e.g., two photos by different photographers) the illustrators’ names are followed by descriptions of their work in parentheses and separated by semicolons (e.g., “Furnald/Gray (robot); John Soares (sewer)”). If multiple credits are given for illustrations in different media, the credits are preceded by descriptions of the media, followed by colons, and are separated by semicolons (e.g., “Photograph: John Soares; Illustration: James Yang”). In such cases, “courtesy of” is used (e.g., “Illustration: courtesy of CityNet; Photograph: John Soares”).

Infographics: Labels in infographics are written in sentence case (first letter of first word cap, first letters of succeeding letters lowercase).


Decks: All decks should be complete sentences and get periods, just like in the national pages.


Letters: Writer responses to letters are introduced by the writer’s full name and the lowercase word “responds”, followed by a colon. Article citations invert the ordinary procedure (i.e., article names and issue dates Roman instead of italic, “TR” italic instead of Roman) and omit the word “see”.

Puzzle Corner: In bridge puzzles, players’ names (compass points) are capitalized. Use numerals for card designations but words for bids, and lowercase suits. Elsewhere in the section, use numerals for designations of numbers qua numbers. In chess puzzles, White and Black are capitalized, but the names of pieces (king, bishop) are lowercased.