As a leading, respected national laboratory, NREL must ensure that its publications and content are accessible to all people. Specifically, we must ensure that everything is '508 compliant.'
Million Ton Product Page
In , Congress amended the Rehabilitation Act of to require federal agencies to make their electronic and information technology accessible to people with disabilities. For example, individuals using assistive technology (such as JAWS, a computer screen reader program) can read a document that is 508 compliant.
All graphs, graphics, animations, fact sheets, and so on must be accessible. Further, videos, animations, and audio files must be 508 compliant. These media types require text versions.
Working with a communications representative will ensure that your content goes through the proper process and is 508 compliant before publishing.
A key part of ensuring 508 compliance involves adding alt text for every figure and photo in technical reports, fact sheets, articles, web pages, social media, and so on. Alt text provides a semantic meaning or description of the image. It can also be read by search engines.
Imagine if, instead of reading a document, you had to listen to it being read to you. By keeping this in mind, you can write alt text that is clear and descriptive. To help, see the following examples of alt text'one for a photo and one for an illustration. For more complicated figures or graphs, try to provide a high-level overview of what is being shown (versus describing every detail).
Alt text: Eagle flying out of a cage with wind turbines in the background.
Alt text: Illustration of spar-buoy, barge, and tension-line floating offshore wind turbines in the ocean, with foundations anchoring them to the seabed.
For more information on accessibility and alt text, review NREL's Communication Standards.
Subjects: Government Terms, Publication Formatting, Publication Policies and ServicesUse "a" before any acronym or word that begins with a consonant sound. Use "an" before any acronym or word that begins with a vowel sound. An acronym is pronounced as a word (for example, a HEPA filter); an initialism is pronounced as its letters (for example, an NGO). The first sound of the word or letters indicates whether to use "a" or "an." Examples: a light-water reactor, an LWR; a Human Resources Office memo, an HRO memo; a nongovernmental organization, an NGO; a National Renewable Energy Laboratory subcontract, an NREL subcontract.
Subject: Grammar and UsageAn abstract usually accompanies a journal article or conference paper. It is an important indexing and research tool. Abstracts are usually 200 to 250 words in length and the content summarizes and highlights the major points of the journal article, conference paper, or report. It may also include a brief description of the purpose, scope, and methods used to reach the conclusions.
Some journals and conferences ask that you submit an abstract that briefly describes the paper's purpose and contents before your submission is accepted. Check with the journal or conference sponsor for guidance on abstract requirements such as length.
The U.S. Department of Energy's Office of Scientific and Technical Information requires an abstract of 200 words or fewer for its citation record posting. This abstract is also typically included in the metadata of the final publication PDF and should briefly describe the context, purpose, and nature of the work and summarize major results or conclusions.
Subject: Publication FormattingAvoid the use of academic degrees unless it's absolutely necessary to establish credentials. If so, use the following abbreviations with periods included after a name and set them off with commas: Ph.D., B.A., M.A., and LL.D. Use them only on first reference. Also, use an apostrophe in bachelor's degree, a master's, etc., but there is no possessive in Bachelor of Arts or Master of Science, for example.
When possible, avoid using Dr. before the names of individuals who hold doctoral degrees, such as Ph.D. Instead, when necessary or appropriate, write out the name of the person's degree.
Katerina Melnyk, who has a doctorate in computational science, was principal investigator. Maxwell Garcia, Ph.D., is joining the IPO directorate.The academic subject of the degree should be lowercase, except for proper nouns.
She has a Master of Science in theoretical physics. He completed a bachelor's degree in English literature at Harvard University. Subject: Writing StyleYou may acknowledge the reviews, funding, and other assistance of individuals and groups in NREL technical reports and papers. Acknowledgments can go in a preface or foreword in a technical report, or they can be on a separate page if they are extensive. They also often follow the main text in professional journal articles. Journals usually contain examples or instructions for authors.
Subject: Publication FormattingTry to write more active-voice sentences than passive-voice sentences. In other words, the subject of most of your sentences should be the "actor" or "agent" (who did it?) rather than the thing "acted upon."
Active voice: We tested the apparatus.Research shows that active voice helps even highly educated readers absorb information more quickly. Passive voice is no longer considered to be more scholarly or scientific than active voice. Active voice also lends clarity and vigor to technical writing. But sometimes passive voice is appropriate, especially when it's more important to emphasize what was done than who did it. Passive voice can add variety to your writing, too. See alsopersonal pronouns.
Subject: Writing StyleUse U.S. Postal Service abbreviations (such as CO for Colorado and DC for District of Columbia) for states in bibliographies, references, and full addresses (those that include streets or post office boxes).
P.O. Box 123In text, when you refer to a state with a city or by itself (for example, "The state
energy office is stepping up solar retrofit activities in Massachusetts."), spell
out the name of the state in full, except for the District of Columbia (D.C.). See
alsostates and countries.
"Affect" is usually a verb, and "effect" is usually a noun.
affect (verb):
The new deposition process affected the efficiency of the device.effect (noun):
We measured the effect of the new process on the efficiency of the device.These words can be confusing because "affect" can sometimes be a noun (when it denotes an emotion), and "effect" can be a verb (when it means "to bring about").
Subject: Grammar and Usage"Air conditioning" is two words when used as a noun and hyphenated when used as an adjective.
Air conditioning is energy-intensive.The Alliance for Sustainable Energy LLC, equally owned and governed by Midwest Research Institute and Battelle, is the manager and operator of NREL (effective Oct. 1, ).
The appropriate term on second and subsequent references is "Alliance" as opposed to the acronym "ASE." Because many companies and groups have ASE as their acronym, this usage will help distinguish the Alliance. Also, because it is used as a proper second reference and not a generic term, the Alliance will remain capitalized for that usage.
Subject: Government TermsAfter spelling out the full name on first reference, you may use "Recovery Act" in subsequent references instead of the acronym "ARRA." But when using "Recovery Act," do not identify it in parentheses after the full name like you would with the acronym.
Subject: Government TermsAmpersands can be used in acronyms, left navigation, right navigation, and in a website's top banner (but not in the heading). Ampersands can also be used as the official name of a company or initiative, for example, PG&E or Leadership in Energy & Environmental Design. Do not use "&" to mean "and" in other situations.
Subject: Writing StyleYou can include detailed background or technical information, derivations, equations, or data tables in one or more appendices. Large, detailed tables are often placed in an appendix. If you have more than one appendix, title them with letters (Appendix A, B, C, etc.). If you have only one appendix, title it "Appendix" rather than "Appendix A." Name figures and tables in appendices so they reflect the title (Figure A-1, Table B-2, etc.). In the case of only one appendix, use the 'A-1' convention for figures and tables.
Subject: Publication Formatting"Assure" means to make sure or give confidence. "Ensure" means to guarantee. "Insure" means to provide or obtain insurance.
The manufacturer assured the group the equipment would work properly.This is the preferred style for NREL reports and papers. Do not use a comma between the author's last name and the year: (Smith ). See also references.
Subjects: Publication Formatting, Writing Style"Bandgap" is one word.
Subject: Technology-Related Terms"Baseload" is one word when used as a noun or adjective.
Subject: Technology-Related Terms"Because" indicates a cause-and-effect relationship. "Since" indicates a time relationship.
Because the equipment malfunctioned, the experiment failed.A bibliography, which is different from a reference list, is a list of works that are related to your subject or publication but not cited, either by author or by number, in the text. Alphabetize works in bibliographies according to the last name of the first author. You may use NREL's reference style in listing the works if you don't have other guidelines (e.g., from a journal). Some bibliographies are titled "For Further Reading." Compile your in-text citations of literature and other sources in a list of references.
Subject: Publication FormattingFollow the general rule for prefixes and do not use a hyphen:
Exceptions include 'bio-based,' 'bio-derived,' and 'bio-oil.'
Subject: Technology-Related TermsWhen used as a noun, 'black start' is two words. Hyphenate 'black-start' when it is used as a modifier. Avoid using as a verb if possible.
This building is capable of black start.BOS stands for balance of systems (not system).
Subject: Technology-Related TermsThe abbreviation for "British thermal unit" is Btu. "Btu" is used for both singular and plural cases.
Subject: Data and MeasurementBullets are printed to the left of items in a list. You must have at least two items in a bulleted list.
Report Formatting
In text, the first level of bullet is indented 0.25 in., and text begins at the 0.5-in.
mark. This level is bulleted with a solid dot. Second-level bullets are open dots,
and third-level bullets are em dashes ('). Each subsequent level of bullet is sequentially indented 0.5 in. In lists
with items that are more than one line, each bulleted item is followed by a 6-pt.
space.
On the Web
For web content (and for PowerPoint slidesand figures), terminal punctuation for a bulleted list is optional when there is no lead-in sentence. Use best judgmentand remember that consistency is key. When formatting bullets on the web, there should
be a space between the text above the bullets and the first bullet. To facilitate
scanning, consider adding a blank line between each bulleted item when the bulleted
text is long. Do not use bullets with lists of links.
1. Proper Nouns
Capitalize proper names. These include the names of government programs, official projects, formal groups, organizations, companies, titles when they precede a name (use lowercase in titles that follow the name), specific geographic areas or features, and ethnic groups.
When referring to NREL, "National Renewable Energy Laboratory" is capitalized, but "the lab," "the laboratory," and "national laboratories" are not.
One exception to this rule is companies and products with stylized lowercase or "camel cap" names (e.g., eBay, iPhone). In these cases, use the company's or product's preferred capitalization.
2. Figure Captions, Table Titles, and Section Headings
Figure captions: Capitalize only the first word and proper nouns in figure captions. No period needed (unless there are multiple full sentences).
Figure 1. Results for the electrochromic window developed at NRELTable titles and section headings: Capitalize the main words of table titles and headings and subheadings, including the second word in a hyphenated term (e.g., "PV Program Five-Year Plan"). No period needed.
Do not capitalize:
Do capitalize:
For journal/conference submissions or other non-NREL publications, follow the style recommended by the professional society or publisher.
3. Titles
Capitalize titles when they precede the person's name. Lowercase titles and names of groups when they follow the name.
4. Trade Names
Capitalize trade or brand names, and include a trademark, copyright, or other symbol only when it's an Alliance-registered trademark. Include the symbol the first time you use the trade name in body text (not in a title, acronym list, or section header); thereafter, you may omit the symbol. Also use superscript for trademark symbols. See the trademark symbols entry for a list of Alliance trademarks.
5. Taxonomic Names
When writing about botanical and zoological divisions, capitalize the names of all
divisions higher than species: genera, families, orders, classes, and phyla. Italicize
genera, species, and varieties.
After you first mention them (and spell them out), you can abbreviate most generic names followed by species names.
See also captions, fiscal year, geographic regions, headings and subheadings, states and countries, and tables.
Subjects: Grammar and Usage, Writing StyleEach substantive photo and image should be accompanied by a caption. Capitalize the first word in a caption and use lowercase thereafter, except for proper nouns and capitalized abbreviations. You don't need a period at the end of a caption unless there is additional text below the caption such as a figure note or the caption includes multiple complete sentences.
For information about figure captions, see figures.
See also photo, image, and video credits.
Subject: Publication FormattingDo not use a hyphen in most chemical expressions, even when the terms are used as modifiers.
carbon dioxide levelsUse a hyphen after prefixes when that's the standard for certain chemical formulas.
L(+)-2, 3-butanediolUse a hyphen to indicate mixtures or combinations.
hexane-benzene Subject: Technology-Related TermsSee references and citations for guidance on author-date and numbered citations.
Subject: Publication Formatting"Cleantech" is spelled as one word. It is not hyphenated, and the "t" is not capitalized. The word "cleantech" is typically used in reference to investments in sustainable technologies, including renewable energy and energy efficiency. Don't use as a shortened form of "clean technology" in other references.
Subject: Technology-Related TermsThe term is "close-spaced sublimation," not "closed-space sublimation."
Subject: Technology-Related TermsColons formally introduce a list or series, a question, or an amplification.
We test three types of collectors: flat plates, evacuated tubes, and parabolic troughs.When the colon is followed by a complete sentence, capitalize the first letter of the first word after the colon.
The relationship between the two is inverse: When volume increases, pressure decreases.Colons also often separate the parts of a ratio.
We added enough water to obtain a 3:1 dilution.However, commas, not colons, usually follow words such as "that is," "namely," and "for example." You don't need a colon after a verb or preposition that precedes or introduces a list ("includes," "to," "with," "between," etc.). Use a colon when a noun (such as "the following") introduces a list in the text.
Subject: Punctuation1. When To Use Commas
Use a comma to separate items in a series, including the next-to-last word in the series.
We develop solar thermal, wind, biomass, and photovoltaic energy technologies.Use a comma to separate the parts of a compound sentence linked by a coordinating conjunction (such as "and," "but," "or," and "nor") when each part has its own subject and verb (unless they're very short).
I laughed at the unintentional joke, but she frowned.Use commas to set off nonessential or nonrestrictive (parenthetical) words, phrases, and clauses from the rest of the sentence. In other words, the commas signal that the information between them is something extra and not essential to the meaning of the sentence.
The subsystem, which takes a day to install, will be delivered in two weeks.Use commas to enclose the name of a state when it follows a city and a year when it follows the month and day.
The test systems in Gardner, Massachusetts, are performing well.2. When Not To Use Commas
Do not use a comma to separate compound subjects or compound verbs.
Theorists and nonspecialists alike agree on the importance of the discovery. (There is no comma between the two parts of this compound subject.)Do not use commas to set off words or phrases that are restrictive (i.e., essential to the meaning of a sentence).
Only the sensors that were attached to the outer edge failed. (The words are essential to the meaning of the sentence.)See also which and that.
Subject: Punctuation"Composed of" is correct; "comprised of" is incorrect. See the examples below.
The United States is composed of 50 states.Capitalize "U.S. Congress" and "Congress" when referring to the U.S. Senate and House of Representatives. Lowercase "congressional" unless it is part of a proper name.
The U.S. Congress is reviewing congressional salaries. A full list is available in the Congressional Record. Subject: Government TermsSee table of contents. For a list of all the content a report may include, see report contents.
Subject: Publication Formatting"Contiguous" means sharing a common border; "continental" means belonging to a continent. In its strictest sense, 'contiguous United States' refers to the lower 48 states in North America (including the District of Columbia), and "continental United States" refers to 49 states (including Alaska and the District of Columbia). However, the terms are often confused and used inconsistently. Best to specify the meaning on first use of the phrase.
Follow the acronym rules if using CONUS, but specify which states the phrase covers on first mention.
Subject: Writing StyleUse lowercase for "cooperative research and development agreement" because it's not a proper noun. On second reference, you can use the acronym "CRADA."
Subject: Government TermsCPV (concentrating photovoltaics) uses lenses to intensify the sunlight striking PV cells, which enhances the cells' electricity production.
Subject: Technology-Related Terms"Criterion" is a singular noun (one criterion), and "criteria" is the plural (two or more criteria). "Data" is the plural of "datum." The plural of "memorandum" can be either "memoranda" or "memorandums." "Phenomenon" is singular, and "phenomena" is plural.
Subjects: Data and Measurement, Grammar and UsageFollow the general rule for prefixes and do not use a hyphen:
cyberattackExceptions: Cyber Monday (n.) and cyber (adj.) as a separate modifier, e.g., cyber shopping and cyber liability insurance.
See the Associated Press Stylebook for more guidelines.
Subjects: Websites, Writing StyleUse dashes (often called "long dashes" or "em dashes") to enclose and set off parenthetical (nonessential but often illustrative) information in a sentence. Also use dashes to set off a list of items separated by commas. Do not add spaces around the dash.
The polymer components of the cell walls'cellulose, hemicellulose, and lignin'provide the feedstocks for these chemicals.Use an em dash to signal that an important point is going to be made or that a change in the construction of the sentence follows.
The presentation concluded with a discussion of the two project factors that concern contractors the most'cost and time.The major omission in the project assessment was the delay caused by the circuit failures'everyone knew about it, but no one mentioned it to the reviewers.
You can usually use commas, colons, and semicolons in place of dashes, but dashes add special emphasis.
Use shorter dashes known as "en dashes" (rather than a hyphen or em dash) to indicate a range or to substitute for the word "to."
25'45 cm2In date spans, do not use "from" in conjunction with an en dash (e.g., "from Jan. 16'Feb. 3"). The correct form is "from Jan. 16 to Feb. 3" or "Jan. 16'Feb. 3."
Do not use an en dash (or hyphen) to mean "and"; the word "between" is followed by the word "and" (not "to"): between 25and 30.
Subject: PunctuationPlace a zero to the left of the decimal in any number less than 1 in text and tables (e.g., 0.5, 0.039). Align columns of data vertically on the decimals. When the units of measurement for the data are different, alignment is not necessary (but be sure to specify the units).
Subject: Data and Measurement'Dataset' is spelled as one word.
Subject: Data and MeasurementDo not include a space before or after the degree symbol.
36°CRepeat the degree symbol in ranges.
32°C'36°CExpress kelvins as K rather than as °K; leave a space before the K.
85 K Subject: Data and MeasurementUse a slash rather than a hyphen.
Subject: Technology-Related TermsExpress thousands of dollars using a comma.
$5,000Express millions and billions of dollars this way.
$3 millionDo not use a hyphen to join a number and words such as 'million' or 'billion,' even when used as a unit modifier.
$4 million prizeIn technical reports and papers, use a dollar sign to express costs less than $1.
$0.25is acceptable in all references for "electronic mail." Use a hyphen with other e- terms: e-book, e-business, e-commerce, e-fuel.
I sent an to everyone involved with the project.The prefix 'eco-' typically includes a hyphen:
Exceptions include 'ecotourism,' 'ecosystem,' and 'ecology.'
Subject: Technology-Related TermsWhen you want to leave out part of text material you are quoting, use ellipsis marks (three dots with a space on each side) to indicate the omission.
A participle is "a word having the characteristics of both verb and adjective ... [that] shows such verbal features as tense and voice. ..."If the words before the ellipses form a grammatically correct sentence, put a period at the end of the sentence and follow it by ellipses. In most cases, however, you don't have to use ellipses at the beginning or end of quotes, just within them. When you add a word or words to the quote, to make it clear, enclose the added word or words in brackets to show that it is not part of the original quotation.
When you quote whole paragraphs but omit text between any two of them, center three asterisks, with spaces between them (* * *), between the paragraphs quoted. See also quotation marks.
Subject: PunctuationENERGY STAR is always in capitals. Use ENERGY STAR® the first time it is used on a page; thereafter, use ENERGY STAR. The ® should be superscript, and there's no space between the ® and ENERGY STAR.
Subject: Government TermsThe preferred term is "enhanced geothermal system." It is also sometimes referred to as an "engineered geothermal system."
Subject: Technology-Related TermsMake sure that all the terms in your equations are defined and used consistently both in the text and in subsequent equations, figures, and tables.
Subject: Data and MeasurementBecause it's vague, use "etc." (et cetera) sparingly. Don't add it to the end of a list beginning with "for example," or the abbreviation "e.g.," because each word in your list is an example of your subject or topic, but "etc." is not, so you don't need it.
Subject: Writing StyleIf you include a summary in a report, place it before the table of contents page. If your report is brief, a summary is not usually necessary. If your report is long, or if you think some readers will want one, you can include an executive summary.
An executive summary can be up to 5% to 10% of the length of your paper. It should be written so that it can be read independently of the full report, as executive summaries are frequently published as a separate document. Its content should include a brief statement of the problem or proposal covered in the report, background information, concise analysis, and the main conclusions. Furthermore, it should be written in plain language, where technical language is defined or examples/further context are provided, making it easy for nontechnical readers to understand.
Figures or tables in the executive summary should be labeled using the format Figure ES-1, Table ES-1.Subject: Publication FormattingUse a capital letter with "federal" for corporate or governmental bodies that use the word as part of their formal names.
Federal Trade Commission, Federal Communications CommissionUse lowercase when the word is used to distinguish something from state, county, city, etc. entities.
federal government, federal court, federal judge Subject: Government TermsFigures can include line drawings, graphs, charts, diagrams, schematics, flowcharts, illustrations, and photographs. Be sure that computer-generated figures are clear and readable, so they can be reproduced easily. Make sure the data in your figures correspond to the data in your text and tables.
Number figures in a simple sequence (e.g., Figure 1, Figure 2). In long reports, papers, or book chapters, you may include section or chapter numbers in the figure numbers (e.g., Figure 1-1, Figure 1-2, Figure 2-1, and so on).
Use 10-pt. Arial bold for captions. The caption is centered under the illustration. For data charts and graphs, use 9-pt. Arial for source lines below the figure. See also captions.
Figure 1. Renewables as a percentage of total installed capacity worldwide
No period is needed after a caption if it is an incomplete sentence (see Figure 1 above). If one or more full sentences follow the incomplete sentence (as a continuing caption or subcaption), each caption (including the opening incomplete sentence) should have a period. Don't bold subcaptions. See Figure 2-1 below for an example.
As required, appropriate credit and Image Gallery information should be provided for figure images. See photo and image credits. Place credit information after the caption.
Figure 2. A Trombe wall at the Zion National Park Visitor Center. Photo by Thomas Wood, NRELSee personal pronouns.
Subjects: Grammar and Usage, Writing StyleSpell out "fiscal year" (e.g., Fiscal Year ) the first time you use it; after that, you can abbreviate it using two capitals followed by a space before the full year (e.g., FY ). FY24 may be used to save space in charts and graphs. On the web, always spell out fiscal year.
Subject: DatesUse Times New Roman for the text of NREL technical papers and reports. Use Arial for figures, tables, and headings.
Subject: Publication FormattingYou can use footnotes to place detailed explanatory or supplementary information at the bottom of a page; use in-text references to cite others' works. Use superscript numerals for footnote numbering. You can also place explanations, details, contradictions, and examples in the text rather than in footnotes. Footnote numbers are printed outside commas and periods but inside colons, semicolons, and dashes.
Mark the footnotes to tables in NREL reports with superscript letters: a, b, c, etc.
Subject: Publication FormattingThe foreword to a book or formal report contains introductory remarks written, and usually signed, by someone other than the author or authors. Brief introductory remarks written by authors are contained in a preface.
Subject: Publication FormattingUse words instead of numerals for simple fractions in text.
Write out complex fractions with numerals separated by a solidus.
Display complex, built-up fractions by centering them vertically between two parts of a paragraph.
Place a zero to the left of the decimal in fractions less than 1.
See also equations.
Subject: Data and MeasurementNREL reports can include front and back matter in the following order:
Front Matter
Back Matter
Paginate front matter with small Roman numerals (i, ii, iii) rather than Arabic numbers. Count the title page as page i, but don't print the number on it. All technical reports should contain a title page, a disclaimer, and a table of contents. Many outreach publications, such as DOE/NREL program overviews, contain only a contents list and brief acknowledgments in the front matter.
Subject: Publication FormattingDo not capitalize "geographic information system" unless used as part of a proper noun. It's also "geographic," not "geographical." Our acronym style guidelines apply as well.
Subject: Writing StyleDon't capitalize words that describe general areas of the country or areas of a state.
the eastern United StatesCapitalize directional words when they designate specific or widely known regions; if in doubt, use lowercase.
Southern CaliforniaIf you use many mathematical or Greek symbols or technical terms in your report or paper, consider defining them in a glossary or nomenclature. Arrange the list alphabetically, and group Greek letters and definitions alphabetically in a separate list. Nomenclatures are usually in the front of a report, before the contents page. Glossaries usually go in the back, before the references.
Subject: Publication FormattingWhen using satellite images from Google Earth and terrain images from Google Maps, include attribution to Google, which is included in Google images with copyright notices such as "© Google, Map Data © Tele Atlas." The Google logo and attribution text can be removed if they are added elsewhere within the image content.
In print, if attribution cannot be placed on the image or map, separate attribution text must be provided directly adjacent to it.
In video, attribution must appear on-screen for the duration of the time the map or image is shown; including attribution in end credits only does not suffice.
If the Google Earth image is altered (e.g., text or graphics are added), the image is legal only if Google Earth software is used to make the alteration and correct attribution is included. Any other alteration of the image using any other software is strictly prohibited.
Derivative works cannot be created. For example, NREL cannot combine multiple static map images to show a larger map.
Subject: Publication Policies and ServicesHere is a standard format for six levels of report subheadings:
First-Level Headings: Arial Bold 18 pt. blue
Second-Level Headings: Arial Bold 14 pt. blue
Third-Level Headings: Arial Bold Italic 12 pt. blue
Fourth-Level Headings: Arial Italic 12 pt. blue
Fifth-Level Headings: Times New Roman Bold 12 pt. black
Sixth-Level Headings: Times New Roman Bold Italic 12 pt. black
Seventh-Level Headings: Times New Roman Italic 12 pt. black
You can number headings and subheadings (e.g., 1.0, 1.1, 1.2, 2.0) if that will help readers with a long report. Print text in 12-point Times New Roman.
Subject: Publication Formatting'High-performance computing' should be hyphenated. The abbreviation HPC can be used to refer to high-performance computing but should not be used to mean high-performance computer. However, the term "supercomputer" may be used in place of high-performance computer.
Subjects: Punctuation, Technology-Related TermsThis phrase contains no hyphens.
Subject: Technology-Related TermsHyphenation rules can be intimidating, but remember that the ultimate goal is to provide as much clarity and consistency as possible. If you can't find the proper hyphenation in this style guide, consult the AP Stylebook, followed by Merriam-Webster.
1. Verb Phrases: Verb, Noun, and Adjective Forms
Verb phrases that contain an adverb (e.g., build up, set up, start up, and break down ) are usually written as two words. The noun and adjective forms of these words are usually one word, although there are exceptions.
We observed the slow buildup of biofouling on the blades.2. Compound Words Containing Prefixes and Suffixes
In most cases, you don't need a hyphen between prefixes or suffixes and the root words.
Exceptions:
Sometimes hyphens are needed when the root word begins with the same letter that the
prefix ends in.
Use a hyphen between prefixes and proper nouns (but not common nouns) or dates whether they're used as nouns or modifiers.
non-NRELUse two hyphens when adding a prefix to a word that already contains a prefix, even when there is no hyphen after the prefix in the original word.
non-self-limitingFinally, these prefixes usually require a hyphen: "ex," "self," and "quasi."
3. Unit Modifiers With and Without Hyphens
Use a hyphen to indicate that words have been combined into a unit modifier, which is a descriptive expression composed of two or more words that form one new meaning. For example, in the term "flat-plate collector," "flat-plate" is the unit modifier. Here are some examples of unit modifiers that usually include hyphens:
low-level radiationTo see how adding the hyphen can prevent confusion, consider these examples:
The scientists tested a new defect causing gas.In the first example, the scientists might seem to have tested a defect; in the second example, it's clear that they tested a gas.
You don't need a hyphen in common unit modifiers that are not ambiguous or confusing.
high school studentsDon't use a hyphen when both words of a unit modifier are capitalized.
Biofuels Program objectivesLeave out the hyphens if you rewrite a sentence so the words in the unit modifier
come after the noun they describe
Don't use a hyphen with a unit modifier containing an adverb ending in "-ly."
heavily skewed resultsDon't use a hyphen with two-word Latin phrases when the phrases are used as modifiers.
candidates for in situ testing at wind farmsWhen you use numbers in unit modifiers, retain all the necessary hyphens. However, do not use a hyphen to join a number and words such as 'million' or 'billion.'
2-ft-diameter tubesOr rewrite the sentence to omit the hyphens.
tubes that are 2 ft in diameterUse suspended hyphens when your compound modifier is interrupted by another word, such as part of a list.
light-, medium-, and heavy-duty vehiclesSuspended hyphens can also be used for different prefixes on the same root word (micro- and mesoscale), but the preferred style is to write out each word fully (microscale and mesoscale). Use your best judgment, considering both the context and audience.
4. Common Hyphenated Terms
Certain words and phrases are always hyphenated, regardless of context. Examples include:
cost-effectiveThis term refers to a cell composed of semiconducting materials from Group III (e.g., gallium) and Group V (e.g., arsenic) elements of the periodic table.
Subject: Technology-Related TermsOfficial company names can use the abbreviation 'Inc.' or the initialism 'LLC' without first defining these terms. Do not use commas around either term.
Alliance for Sustainable Energy LLCAn initialism is similar to an acronym, but it is pronounced by its letters.
Use a small s (no apostrophe) for plurals of most initialisms (e.g., PUCs and CFCs, not PUC's or CFC's).
Avoid the use of initialisms unless they are used extensively in a document. In short reports, spell out initialisms that are used fewer than five times. In long reports, spell out initialisms that are used fewer than 10 times. If initialisms are used, spell them out on first use, and put the initialism in parentheses after the full name.
To avoid confusion, try not to use too many in any sentence or paragraph. Include a glossary or list of acronyms if your publication contains a lot of them.
On the Web
The above guidelines apply to web content as well. However, if you use an initialism,
spell it out or define it the first time you use it on each webpage. On the web, spell
out initialisms that are used fewer than three times.
If your audience is international, consider following an international style guide such as the United Nations Editorial Manual. If your text is in English, consider using British English. Use plain language. Keep sentences short. Write in active voice when possible. Avoid idioms and colloquialisms. Be aware of differences in style for currencies, dates, units, and addresses.
If you choose to translate content and are trying to reach a wider audience, select a standard dialect of Arabic, Chinese, an Indian language, or Spanish. Your NREL communications representative can help you choose both the appropriate translation for your audience and a contractor to provide the translation. If you translate content, have it reviewed by a person fluent in that language. NREL has a list of bilingual staff members who can help read, write, and translate many languages. Your NREL communications representative can provide you that list.
Subject: Writing StyleLowercase "internet," except for the specific phrase "Internet of Things" (abbreviated IoT).
Subjects: Websites, Writing StyleIntroductions usually contain background information on the research being reported, the general nature and context of the work, and its results (the "big picture"). Earlier related work can also be described.
Subject: Publication FormattingInverters convert direct current to alternating current.
Subject: Technology-Related Terms1. Using Italics for Emphasis
Use italics (sparingly) to emphasize a word or phrase or bring attention to it.
Never operate this equipment when it has a yellow danger tag.2. Using Italics for Foreign Words and Phrases
Italicize such foreign words and phrases as terra incognita, in vivo, and inter alia; however, if the word or phrase is commonly used in your field (e.g., in situ, et al., ad hoc, ab initio), you may omit the italics.
3. Using Italics for Hyphenated Prefixes
Italicize hyphenated prefixes (such as cis-, trans-, o-, m-, and p-) to chemical formulas.
trans -1, 2-dibenzoylethylene4. Using Italics To Cite Published Documents
Use italics for the names of books, journals, newspapers, magazines, and reports.
Clean Energy Innovators: NREL People Working to Change the WorldIn print, the titles of journal and magazine articles are listed in regular roman type within quotation marks. On the web, omit the quotation marks.
"Solar Chimney Theory: Basic Precepts"5. Using Italics in Taxonomic Names
Unless you're discussing a genus in a general way, use italics to refer to specific genera, species, and varieties.
Clostridium thermocellumEven though "it's" has an apostrophe, it isn't a possessive pronoun. "It's" is a contraction, a short form of two words, like "isn't." "It's" always means "it is." "Its" is the possessive form of "it." Like "his," "hers," and "ours," the possessive "its" never needs an apostrophe.
It's a shame that the company lost its biggest investor. Subject: Grammar and UsageOnly capitalize "laboratory" or "lab" when used with a laboratory's full name. Lowercase in all other references.
The National Renewable Energy Laboratory is a U.S. Department of Energy national laboratory. The laboratory is known for its research and development in renewable energy and energy efficiency. Subject: Writing Style"Lightbulb" is spelled as one word.
Subject: Writing StyleYou can use bulleted or numbered lists in NREL publications or web pages. Here's an example of a numbered list:
You can also list a few items or procedures in paragraph format and number them (1) one, (2) two, (3) three, etc. See bullets for more formatting information.
On the Web
All of the above guidelines apply to the web. When formatting lists on the web, there should be a blank line between the text above the list and the first item listed. To facilitate scanning, consider adding a blank line between each listed item when the text for each one is long.
Subject: Publication FormattingLeave a space on either side of mathematical symbols used as operation signs.
The solidus (a/b) or division sign is an exception. Do not leave a space between numerals and the symbols for degrees, dollars, and percent (32°, $100, 17%). (However, leave a space between numerals and symbols of measurement such as cm and Å.) Do not leave a space between symbols such as >, <, and ' and the numeral unless they are the operation signs in an equation.
Subject: Data and MeasurementFor quick online conversions of English units of measurement to metric units, see the Digital Dutch WWW Unit Converter website or IFP Reference Conversions on the French Property website.
Subject: Data and Measurement"Microgrid" is spelled as one word.
Subject: Writing StyleModifiers in the wrong place can make a sentence confusing.
After identifying the correct material, the test procedure took about 5 minutes.In this example, it isn't clear who or what identified the correct material. This might be better: After identifying the correct material, we conducted the 5-minute test procedure.
After being lost under a pile of old reports for 5 years, she finally found the manuscript.What, or who, was lost'the manuscript, the woman, or the reader? Try to keep modifiers as close as possible to the people and things they describe. Strunk and White, authors of The Elements of Style, say this: "Modifiers should come, if possible, next to the word they modify." This is especially true for sentences containing introductory prepositional phrases or clauses followed by a comma.
Subject: Grammar and UsageCapitalize the months in all uses. When a month is used with a specific date, abbreviate only Jan., Feb., Aug., Sept., Oct., Nov., and Dec. (Jan. 9, ). Also abbreviate these months in tables; however, omit the period. Spell out months when used alone or just with the year, and omit commas when the month and year appear together (October ).
Use a lowercase s (no apostrophe) to show the plural of a decade expressed with numerals (e.g., the s).
Subject: DatesThis term is preferred over "tandem solar cell."
Subject: Technology-Related TermsBe as consistent as possible in using multiplication symbols in your paper or report. As appropriate, choose one symbol (× or ·), or omit the symbol and use proximity or parentheses: ab, (ab) (cd), etc.
Subject: Data and MeasurementAlways use lowercase for the word "nation" when referring to the United States.
Our nation is a leader in renewable energy markets. Subject: Writing StyleWhen used as a noun, 'net zero' is two words. It is also two words when referencing the Net Zero Labs program. Hyphenate 'net-zero' when it is used as a modifier.
NREL is eliminating its carbon footprint through the Net Zero Labs initiative.Spell as one word. Don't hyphenate.
Subject: Writing StyleA nonrestrictive phrase or clause is one that adds information but is not essential to the meaning of the sentence.
The principal investigator, who has studied thin films for 10 years, will chair the panel discussion.The passive solar features, which were suggested by NREL staff, reduced the agency's energy bills by 30%.
Nonrestrictive or nonessential phrases and clauses are enclosed between two commas when the phrase or clause is within a sentence, and they usually begin with "which" rather than "that." See also restrictive phrases and clauses and which and that.
Subject: Grammar and UsageUse non-SI (Systeme International d'Unites) or nonmetric units of measurement (English or Imperial units) instead of metric units only when they are the industry standard. Otherwise, state metric units first, followed by English equivalents in parentheses.
38.1 m (125 ft) Subject: Data and MeasurementTry not to string too many nouns and adjectives together in a sentence. An "agency personnel communications interface display" could also be called a "display of the communications of the agency's personnel." Better yet, it could just be called the "staff bulletin board."
Subjects: Grammar and Usage, Writing StyleTo give your writing more flow and vigor, try changing some of the nouns (especially those ending in -tion and -ment) to verbs (e.g., determine, complete, accomplish, achieve, measure, convert, characterize, combine) and other parts of speech. Doing this will move your readers along more quickly and make it easier for them to understand your text. In these examples, we changed some of the nouns in the first sentences to verbs and other parts of speech.
Contraction of the tree stems occurred with rapidity.Which sentences were easiest to read and understand?
Subject: Grammar and UsageThe NREL attribution statement, which recognizes NREL's affiliation with the U.S. Department of Energy and the Alliance for Sustainable Energy, is required on all NREL publications. In addition, note that a period is used on the "sentence" version of the statement.
Subject: Government Terms1. Units of Measurement and Mathematical Expressions
Use numerals with units of measurement and time.
With units of time, you can spell out numbers less than 10 if you do so consistently (this applies mainly to outreach products rather than technical reports and papers).
five-year planUse numerals to imply arithmetical values or manipulation.
a factor of 3Express measurement errors as:
6.0 nm ± 0.2 nm.Leave a space between the number and the unit of measurement (0.2 nm) and put spaces around the operation sign. When the measurement error appears by itself, omit the space between the sign and the number.
The measurement error is ±0.2 nm.2. Aligning Numbers
Align numbers that share a common unit of measurement on the decimals in columns of tables. Put a zero before the decimal in numbers smaller than one.
If all the numbers in a column do not share the same unit of measurement, you may center the numbers in the column and specify the unit of measurement.
3. Fractions and Decimals
You can spell out and hyphenate simple fractions (this is preferred in text) or express them, like more complex fractions, in numerals with a solidus.
one-fifth or 1/5Use a hyphen to separate the integral and fractional parts of a mixed number, or convert the fraction to a decimal.
2-1/2 cm in diameterFor numbers of 1 million or more, use the numeral (and a decimal, if necessary) and the words million, billion, etc.
1.1 million households4. Precision and Numbers
Measurement uncertainty analysis calls for precision in measurements to a significant digit to the right of a decimal point, such as two or three digits (hundredths or thousandths). If you're not absolutely sure, check with an expert before changing the number of digits to the right of the decimal, or rounding the numbers. See also standard errors.
5. Punctuating Numbers
Use a comma to separate groups of three digits in numbers.
5,1826. Ranges of Numbers
To show ranges, use an en dash (which is a little shorter than an em or long dash) with no spaces. Alternatively, if you write out a range, make sure you use the word "to" when you use "of" or "from" before the range. To express a range between some number and another number, always use the word "and" (not "to") with the word "between."
15%'25%Note that some symbols, such as ° and %, are repeated in a range.
7. Scientific Notation
Express multiples of SI (metric) units in powers of 10 with the appropriate prefixes and technical abbreviations.
mm (millimeters, 10-3 m)Use standard scientific notation to express very small and very large numbers.
2.5 × 10-3Avoid using M to mean "thousands" and MM to mean "millions"; use a capital M for "mega," or millions, as in MW for "megawatts."
8. Spelling out Numbers
Except with units of measurement and time (in technical reports), spell out numbers less than 10.
eight experimental runsSpell out all numbers at the beginning of a sentence.
Fifteen trials later, the results were the same.In general, spell out numbers at the beginning of a bulleted item, but use best judgment depending on the context (e.g., a list of sentence fragments using numbers with many digits).
When a sentence contains one or more numbers greater than nine that are related to a smaller number, use numerals for all of them.
The results were the same in 3, 12, and 18 trials.Spell out the first of two adjacent numbers unless the first one requires three or more words.
ten 5-kW arraysSee also fractions.
Subject: Data and MeasurementIn cases involving quantity, use "more than" rather than "over," and use "fewer than" or "less than" rather than "under." In cases involving temperature, use "higher than" or "lower than" or "warmer than" or "cooler than." In cases involving weight, use "heavier than" or "lighter than."
More than 500 people attended the conference, about 100 fewer than last year. Subject: Grammar and UsagePaginate the front matter of NREL reports with lowercase Roman numerals, up through the lists of figures and tables. The title page is usually page "i," although that number isn't printed on the page. Paginate the main body of your report with Arabic numerals. You may insert a blank page before Page 1 to make sure it will be a right-hand (odd-numbered) page, but don't insert blank pages after that. All subsequent sections can begin on the left or on the right, as they fall. Center the page numbers on each page.
If you include appendices at the end, you may continue to paginate them sequentially with numerals or use A-1, A-2, A-3, B-1, B-2, and so on, for the page numbers.
Subject: Publication FormattingUse parallel construction in sentences as well as in lists. Express all similar sentence elements (subjects, verbs, verbals, objects) in a similar way.
Parallel Structure:Use parentheses as appropriate for explanatory material in text and as shown in the examples that follow.
1. Parentheses in Equations
In equations, use parentheses, brackets, and braces in this sequence (which may be repeated as needed).
{[( )]}2. Parentheses with Measurements
Use parentheses around English measurements that follow SI (metric) measurements.
3.1 m/s (7 mph)3. Parentheses in Citations
When you use parentheses in text, such as for author-date references or for parenthetical (added) information, place a comma after the parentheses rather than before them.
In earlier research (Jones ), we showed how quantities of lipids could be increased by this method.4. Nested Parentheses in Text
In body copy, use parentheses, brackets, and braces in this sequence, which may be repeated as needed: ([{ }]).
(The data presented here [originally derived from Mason {}] should not be used for location-specific analyses.) Subject: PunctuationUse the symbol % with numerals; use the word "percent" when you spell out numbers at the beginning of a sentence. To determine whether "percent" or % is singular or plural, look at the noun following it. If the next noun is a plural, use a plural verb; if it's singular, use a singular verb.
The maximum glucose yield was 60%.When there is no number, use the word "percentage," unless people in your field use a different terminology, such as "percent difference."
This table shows the percentages of government buildings having solar roofs, by state. Subject: Data and MeasurementPeriods are used in some abbreviations (e.g., i.e., a.m., p.m.) and not in others (ac, dc, rpm). Most acronyms do not have periods. When you end a sentence with "etc." (although this is seldom necessary) or another abbreviation that includes a period, do not add another one.
This paper describes the program's purpose, objectives, schedule of deliverables, etc.First-person pronouns may be used in technical communications when appropriate, and some scientific and technical associations (such as the American Institute of Physics) encourage technical writers to do so. Common first-person pronouns include "we," "our," and "us." Personal pronouns can prevent confusion by clearly and concisely showing who performed an experiment or procedure.
We tested several hundred isolates that were able to ferment glucose.Which of the following two sentences is easier to read and understand quickly?
It was determined that the workshop was a success.See also active voice and passive voice.
Subject: Grammar and UsageDo not use parentheses around area codes in numbers. Parentheses previously were used to set off the three-digit code in a number because it wasn't always necessary when dialing the number. However, they are required in most instances now.
Use hyphens to separate the digits in numbers.
303-275- 1-800-555- Subject: GeographyIf you use a photo, image, or video from the NREL Image Gallery, an NREL staff member, or a paid or external source, you must provide appropriate credit. See the entries on captions and sources for more information, as well as the copyrighted material page on the publishing site.
For photos, images, and video on the web, include the credit after the caption and italicize it.
Use "from" for external sources and "by" for NREL sources. Do not use "courtesy of."
The National Wind Technology Center at NREL is located south of Boulder, Colorado. Photo from Joe Smith The National Wind Technology Center at NREL is located south of Boulder, Colorado. Photo by Jennifer Josey, NRELDon't include image numbers in the credit. Instead, the photo image file name should include the image number so it can be easily located in the Image Gallery if needed.
Subject: Publication Formatting"Photovoltaics" is a singular noun. "Photovoltaic" is an adjective. The acronym PV can be a noun or an adjective, but do not pluralize it.
Subject: Technology-Related Terms"Policymaker" and "policymaking" are both spelled as one word.
Subject: Writing StyleBrief introductory remarks and acknowledgments go in the report's preface. The preface comes after the title page and disclaimer page. (See front matter.) A preface written by someone other than the authors of the report is usually called a "foreword."
Subject: Publication FormattingSee hyphens, compound words, and unit modifiers and scientific notation.
Subject: Grammar and UsageUse the standard SI unit for pressure or stress, which is the pascal (Pa) or the bar. Non-SI units include psi (pounds per square inch), millimeters of mercury, torr, and atmospheres, and they are still in relatively widespread use.
Subject: Data and Measurement"Principal" often means "chief" or "main," such as the principal investigator in a research project or the principal of a high school. "Principle" often refers to a belief, value, or rule.
Subject: Grammar and UsageUse quotation marks for direct quotes and the titles of articles, papers, and book chapters. In print, use "curly" or "fancy" quotation marks; on the web, use "straight" quotation marks.
"Let's meet again in 6 months," the chairman said, "to discuss our progress."Place commas (and periods) inside quotation marks; place semicolons, question marks, dashes, and exclamation points outside quotation marks unless they're part of the quotation.
"The results are in," he said.Use single quotation marks to indicate a quotation within material that is already enclosed in double quotation marks.
"Explain what you mean by 'confidence,'" she said.When quotations are longer than two or three lines of text, begin them on the next line and indent them on each side (block quotations). You do not need quotation marks around block quotations, and you can use standard double quotation marks for quotes within block quotations. In in-text quotations, place reference numbers, superscripts, and author-date citations outside quotation marks (but before the final punctuation of a sentence). Place them after the final punctuation of the last sentence in a block quotation.
Subject: PunctuationAs a laboratory that strives for diversity of perspectives and inclusivity, our word choices, style, and tone must be carefully considered, particularly when it comes to topics related to race and ethnicity.
Capitalize Black when referring to African Americans or, more broadly, in any racial, ethnic, or cultural sense; do not capitalize white. Do not use the terms 'Black(s)' or 'white(s)' as singular or stand-alone nouns referring to a person or people. In the plural form, 'Black people,' 'white people,' 'Black scientists,' and 'white scientists' are preferable when clearly relevant.
NREL's Black Employee Resource Group focuses on developing and supporting a vibrant community for NREL staff that identify as Black or of African descent.Capitalize 'Indigenous' in reference to original inhabitants of a place, aligning with long-standing capitalization of other racial and ethnic identifiers such as Latino, Asian American, and Native American. (Note that no hyphen is used in dual heritage terms such as 'Asian American' and 'Mexican American.') Capitalize 'Elder' when referring to a Tribal or religious leader, but lowercase it when used to identify someone by age or when used generally.
For more 3.1m Large Format Sublimation Paperinformation, please contact us. We will provide professional answers.
The research team visited Indigenous communities throughout the Midwest to gather insights from local Elders.The terms 'Tribal' and 'Tribe' should be capitalized, even when they are not part of an entity's official name. Capitalize the word 'nation' when part of a formal name.
the Kenaitze Indian TribeIn Alaska, the Indigenous groups are collectively known as Alaska Natives. Both 'American Indians' and 'Native Americans' are acceptable terms when referring to two or more people of different Tribal affiliations. 'First Nation' is the preferred term for native Tribes in Canada. 'Indian' is used to describe the peoples and cultures of the South Asian nation of India and should not be used as shorthand for American Indians, unless that is how a particular group prefers to be referenced.
NREL staff worked with Alaska Natives and First Nation Tribes to design specialized heating equipment.For additional details, refer to the AP Stylebook's race-related coverage.
Subject: Grammar and UsageIn general, use a colon to indicate a ratio.
We prepared a 3:1 dilution.However, some industries (such as the American automotive industry) use a solidus to express a ratio.
The engine is designed to have an optimum air/fuel ratio. Subject: Data and MeasurementDon't capitalize "renewable energy certificate." It's not a proper noun. Also, this is the term preferred over "renewable energy credit" or "green tags."
Subject: Government TermsOnly capitalize "renewable portfolio standard" when a state name precedes it.
Renewable energy certificates have been proposed under California Renewable Portfolio Standards. Subjects: Government Terms, Technology-Related TermsReport contents may include (in order):
See also front matter and back matter.
Subject: Publication FormattingNREL uses standard covers for most technical reports and papers and subcontract reports. Covers contain the laboratory's name, address, and logo as well as an NREL report number and date of publication. You may spell out an author's first name with or without a middle initial or use initials for the first and middle name.
Subject: Publication FormattingUse "Research Support Facility" (RSF), regardless of which phase or wing is cited.
The Research Support Facility is designed to be a model for sustainable, high-performance building design. Construction on the first phase of the Research Support Facility, which is 222,000 ft2, was completed in summer . Subject: Government TermsDo not use commas around restrictive phrases and clauses. They are essential to the meaning of the sentence, in contrast to nonrestrictive phrases and clauses, which simply add information that is not essential.
This is the house that Jack built.See also which and that.
Subject: Grammar and Usage'Roadmap' should be used as one word when referring to a plan or document laying out progress or steps toward a goal. 'Road map' should be two words when referring to a tool used to navigate or travel via roadways, such as by vehicle.
Standard scientific notation represents a number as a factor multiplied by a power of 10; 3,560,000 is expressed as 3.56 × 106. This is useful for very large and very small numbers, especially in non-SI units. You can also use certain standard prefixes, many of which are listed here with their abbreviations.
We recommend choosing a prefix that permits the numerical value to fall between 0.1 and 1,000 (62 kW rather than 62,000 W).
Subject: Data and MeasurementSemicolons indicate a stronger or more important break in the flow of words than the break indicated by a comma. Use a semicolon in compound sentences that are NOT linked by a conjunction (such as "and," "but," "or," "nor," and "yet"). Place a semicolon before conjunctive adverbs (such as "however," "hence," "therefore," "nevertheless," and "consequently") in most complex sentences containing two or more clauses. When a sentence contains items in a series, you may use a semicolon between the items if one or more of the items contains commas.
1. Using Semicolons in Compound Sentences without Conjunctions
When clauses in a sentence are closely related in meaning, a semicolon is an appropriate dividing punctuation mark. Note that the words "and," "but," "or," and "nor" do not follow semicolons.
It was difficult to reproduce the experiment; the material Smith and Jones used was not widely available. Of the 13 samples, only one did not degrade; others deteriorated an average of 8%.2. Using Semicolons with Conjunctive Adverbs
"Yet" and "so" are usually preceded by commas in a complex sentence. But use a semicolon before such conjunctive adverbs as "then," "however," "thus," "therefore," "hence," "accordingly," "moreover," "nevertheless," "consequently," "besides," "indeed," and "subsequently"; place a comma after the adverb.
The contractor's representative was out, so I left a message.We used the Schartz-Metterklume method in the experiment; however, the problems with this method are well known.
Energy requirements are often expressed in quads, or quadrillion Btu; therefore, this report describes the number of quads supplied annually by each option.
Use a semicolon before "i.e." ("that is") and "e.g." ("for example") and a comma after them when a clause (with a subject and verb) follows them; use a comma when a phrase or list follows.
3. Using Semicolons in a Series
When items in a series contain internal punctuation (e.g., commas) or are very long, you can separate them with semicolons. In those cases, a conjunction can follow the last semicolon.
The contaminants in the sample were TCE, 150 ppb; toluene, 220 ppb; and benzene, 265 ppb.Promising new technologies demonstrated at the exposition included advanced wind turbines; polycrystalline, thick-film, and thin-film solar cells; fast-growing energy crops; and fuel cells.
The vendor assured us that the replacement parts, which were essential in this installation, were on order; that the parts would be delivered as soon as they arrived; and that the delay in shipment was unavoidable.
Subject: PunctuationNREL follows national policies and those of scientific societies by using the SI (Systeme International d'Unites, International System of Units) or metric system in expressing technical measurements. English units may follow metric ones or may be used alone in special cases, when that is appropriate for a publication's audience. See also the National Institute of Standards and Technology.
Subject: Data and MeasurementThe solidus (or slash, slant, shilling mark, or virgule) is a versatile symbol that has mathematical as well as textual functions.
1. Using a Solidus in Fractions
Use a solidus to express a quotient in text when you do not need to use a displayed equation.
These structures yield photoluminescence lifetimes that are related to bulkUse a solidus in superscript and subscript fractions.
x1/22. Using a Solidus in Text
In text, use a solidus to indicate some junctions, interfaces, and components.
gas-liquid interfaceWith abbreviated units of measurement, the solidus stands for "per."
2 g/cm2But spell out "per" when you spell out the units of measurement.
several cubic meters per secondUse capital letters for "Smart Grid" when referring to the overall goal or concept and lowercase letters for "smart grid" when referring to current implementations or when used as an adjective.
Subject: Technology-Related TermsUse a slash rather than a hyphen to designate solar cell interfaces or layers.
CdTe/CdS2Define in outreach publications as "the percentage of sunlight striking a solar cell that is converted into electricity." A definition is often unnecessary in technical publications.
Subject: Technology-Related TermsThis term is interchangeable with "photovoltaic power," "PV power," or "PV electricity."
Subject: Technology-Related TermsInclude the sources of all figures and tables that were originally published by others, especially those outside NREL. If figures or tables come from a copyrighted publication, you may need permission to reproduce them. Add the source at the end of a figure caption or in a note following a table.
Source: Hansen, W.L.; Pearton, S.J.; Haller, E.E. (). Appl Phys. Lett. 44:606.Write out the source in full, as in the example, if it is not in your reference list or bibliography. If it is in the reference list, use one of these styles.
Source: Hansen, Pearton, and Haller .Use only one space between a period and the beginning of the next sentence.
Subject: Publication FormattingIf you can't find a word or phrase in this style guide, consult the following reference guides in this order: (1) The Associated Press Stylebook and (2) Merriam-Webster's Collegiate Dictionary, Eleventh Edition.
For spelling out numbers, see numbers.
Subject: Grammar and UsageExpress standard measurement errors as shown below.
6.0 nm ± 0.2 nm Subject: Data and MeasurementCapitalize "state implementation plan" only when a state or organization name precedes it.
The Connecticut Department of Environmental Protection incorporated emission reduction strategies into its U.S. Environmental Protection Agency State Implementation Plan for air quality. Subject: Government Terms1. States
In text, consistently spell out states' names rather than using U.S. Postal Service abbreviations.
California (rather than CA)You may use D.C. for the District of Columbia in text, in both formal and informal publications. When you include addresses or state names in full addresses (containing streets and cities), contact lists, reference lists, and bibliographies, however, you may use the following abbreviations:
AL, AK, AZ, AR, CA, CO, CT, DC, DE, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY (PR, VI)2. Countries
Do not abbreviate the names of countries (including the United States) when they are used as nouns. Use "U.S." as the adjective form.
the United StatesWhen referring to statistical or graphical terms, use a hyphen but no italics. Also, do not use capital letters.
p-valuePrint captions to figures and photos in a bold font. Subcaptions are supplementary information that follows a period after the main caption. Subcaptions are not printed in bold.
But follow the publisher's guidelines for journal articles and conference papers.
Subject: Publication FormattingThe correct term is "systems integrator," not "system integrator."
Subject: Technology-Related TermsA table of contents is required in most technical reports. In NREL reports, the table of contents follows the rest of the front matter. Lists of figures and tables follow the contents page(s). Each main section of the report is listed in the table of contents with the page it begins on; some authors also like to list subsections. Nothing that comes before the table of contents (front matter) is listed, but references, bibliography, and appendices (back matter) are listed. Publications for general audiences probably should include a contents list if the publication is more than 10 pages long.
Subject: Publication FormattingIn small or average-sized tables, place a horizontal line (as wide as the table) under the title, under the column headings, and below the table (between the table and sources or notes, if any). Delete vertical lines and extra horizontal lines. If the table is very large, shading every other line with a light color or inserting horizontal lines every three or four rows can help readers locate data.
Number tables in simple sequence or by section in long reports (Table 1, Table 2 or Table 1-1, Table 1-2, and so on). Center the table title (in title case) over the table (unlike a figure caption, which is sentence case and goes under the figure) and print the title in 10-pt. Arial bold; supplementary material in the title is not in bold. If possible, print tables in Arial, rather than Times New Roman. Define abbreviations in notes to the table if they are not obvious. Table notes are denoted by lowercase superscript letters (a, b, c) rather than footnote numbers or asterisks.
Subject: Publication FormattingSee capitalization and italics.
Subject: Writing StyleUnless your profession, technical field, or scientific discipline specifies something different, use the abbreviations in NREL's list of technical abbreviations or the National Institute of Science and Technology's Guide.
Subjects: Data and Measurement, Technology-Related TermsHyphenate. Don't spell as one word.
Subject: Technology-Related TermsUse a degree symbol (°) with temperatures expressed in the Celsius and Fahrenheit scales but not with kelvins (just use K). Don't leave a space between the number and the letter for °C and °F, but leave a space between the number and K.
72°FSee which and that.
Subject: Grammar and UsageMost NREL technical reports contain a standard title page inside the cover.
Subject: Publication FormattingSee International and Non-English Speaking Audiences.
This is the preferred term for printed and outreach materials. When spelling it out, "U.S." should precede "Department of Energy" to distinguish it from other state and international departments. However, "U.S." should not be included with the acronym "DOE." Do not include "the" before "DOE."
On first reference, "Energy Department" may be used in communications to the press.
If the possessive is used with the term, the apostrophe should go after "U.S. Department of Energy" and with the "DOE" acronym as well. However, if you can write it in a way that avoids use of the possessive, that is preferred.
The U.S. Department of Energy's (DOE's) priorities include combating the climate crisis, creating clean energy union jobs, and promoting energy justice. Subject: Government TermsSee hyphens, compound words, and unit modifiers.
Subject: Grammar and UsageSpell out "United Kingdom" when it is used as a noun. The abbreviation "U.K." is acceptable when it is used as an adjective.
Interest in renewable energy in the United Kingdom has increased in recent years. New U.K. targets for reductions in carbon emissions have increased interest in renewable energy. Subject: Writing StyleSpell out "United States" when it is used as a noun. The abbreviation "U.S." is acceptable when it is used as an adjective.
The United States is a leader in renewable energy markets. The global markets for renewable energy are stronger than the U.S. markets. Subject: Writing StyleUse numerals with units of measurement and time in technical papers and reports, even when the number is less than 10. In some outreach publications, you may spell out numbers less than 10, especially with units of time.
Except with $, °, and %, leave a space between the numeral and the unit. Include a hyphen between a numeral and an abbreviated unit when the value is used as an adjective.
Do not include a period after a unit symbol except at the end of a sentence. The exception to this rule is inches (which are abbreviated 'in.').Avoid nonstandard abbreviations such as sec or cc, and instead use standard abbreviations such as s and cm3. Unless your profession, technical field, or scientific discipline specifies something different, use the abbreviations in NREL's list of technical abbreviations or the National Institute of Standards and Technology (NIST) guide.
Use a center dot to indicate multiplication of units (such as N'm for Newton-meters), and use a slash or negative exponent to indicate division. For example, 344 meters per second can be written as 344 m·s'1 or 344 m/s.
Format variables in italic type and units in roman type:
Correct: t = 3 s, where t is time and s is secondsDo not mix information with unit symbols or names:
Correct: the water content is 20 mL/kgAvoid mixing symbols and names; for example, use kg/m instead of kilogram/m.
When expressing a range, repeat the unit symbol if it is closed-up with the numeral ($, °, %):
10%'20%Refer to the NIST style conventions checklist for additional style tips and examples.
Subject: Data and MeasurementUniform resource locators, or URLs, are essentially web addresses.
On websites, URLs should be embedded in text.
More information is available on the NREL website.In print, URLs should not be embedded in text. If a URL extends beyond one line of text, add a break at a solidus. Also, in general, you do not need to include the http:// prefix on most URLs. But test it before removing it. Shorten URLs as much as possible (e.g., remove unnecessary trailing such as /index.html) while ensuring functionality.
Subjects: Websites, Writing StyleThe following words are lowercase:
"World Wide Web" is a proper noun and should be capitalized.
Subjects: Websites, Writing StyleFor website content guidance, see Content and Writing for NREL.gov. We use the NREL Style Guide in conjunction with these guidelines and standards. Some specific NREL style guidelines, which are different from print style, for the web include:
Abbreviations and acronyms
Ampersands
Bullets
Fiscal year
Initialisms
Lists
Photo credit
URLs.
Subjects: Websites, Writing StyleStandard American English uses "which" is a thing for nonrestrictive or nondefining phrases and clauses and "that" for restrictive or defining phrases and clauses. The word "which" usually signals the approach of added, nonessential information. When a phrase or clause is not essential to the meaning of a sentence, use the relative pronoun "which" and enclose the phrase or clause in commas. See also nonrestrictive phrases and clauses and restrictive phrases and clauses.
This paper, which she has been working on for three weeks, discusses string theory.When a phrase or clause is essential to the meaning of a sentence (that is, the sentence would not make much sense without it), use "that" and leave out the commas.
The paper that he completed recently will be presented in New York; the paper that he finished last summer will be presented in Philadelphia. Subject: Grammar and UsageUse lowercase for "work-for-others agreement" because it's not a proper noun. The acronym "WFO" refers only to work for others; therefore, when using the acronym, "WFO agreement" is correct.
Subject: Government TermsFor numbers less than one, place a zero before the decimal.
0.5Use the term to indicate an energy-efficient building where, on a source energy basis, the actual annual delivered energy is less than or equal to the on-site renewable exported energy. Similar terms include zero energy campus, zero energy portfolio, and zero energy community.
Subject: Technology-Related TermsAn abbreviation is a shortened form of a word used in place of the full word. An acronym is a word formed from the first letters of each of the words in a phrase or name. An initialism is similar to an acronym, but it is pronounced by its letters.
Include a glossary or list of acronyms if your publication is at least 50 pages and contains at least 20 acronyms.
Abbreviations
Acronyms
Initialisms
Spell out the full name on first use, followed immediately by the abbreviation/acronym/initialism in parentheses. To avoid confusion, try not to use too many in a sentence or paragraph.
Avoid abbreviations, acronyms, and initialisms unless the phrase appears more than once or if they are better recognized than the full name (e.g., NASA, PG&E). Similarly, avoid using in headlines or page headers unless well recognized.
Exception: Acronyms and initialisms may be used for EERE News and blog items distributed via GovDelivery. Headlines should be written to be relatable and easy to understand.
Common abbreviations/acronyms/initialisms that do not require spelling:
Web content. The above guidelines apply to web content as well, but try to avoid abbreviations/acronyms/initialisms, especially in headers and webpage or article titles, and use a shortened version of the name on second reference. If you can't avoid, define it the first time used on each webpage.
Technical measurement units. Spell out a technical abbreviation in full in text when used without numerals.
Abbreviate units of measurement when they are used with a numeral or numeric value. With a few exceptions (such as %, °, $, <, and ¢), use a space to separate them from numerals.
In text without numeral: 'a few centimeters' not 'a few cm.'
In text with numeral:
Pluralization. Use a small s (no apostrophe) for plurals of most abbreviations. For plurals of units of measurement, omit the s.
Possessiveness. If the possessive is used with a name or term, the apostrophe should go after the spelled-out name or term and also with the acronym/abbreviation/initialism. However, preference is to write in a way that avoids use of the possessive.
The U.S. Department of Energy's (DOE's) Office of Energy Efficiency and Renewable Energy (EERE) is in charge of the program.
Abbreviating equations and references. You can abbreviate 'equation' and 'reference' when used with numbers. Spell them out at the beginning of a sentence.
See Eq. 1-1, Eq. 2-7, and Ref. 10.
Equation 2-1 shows the relation.
Abbreviating in journals. For a journal article, consult the publisher's or professional society's guidelines for abbreviations, if available.
A bulleted list requires at least two items.
Make bulleted lists parallel in construction (begin all the items in the list with the same part of speech, such as a verb or a noun).
Punctuating bulleted lists. Begin each item with a capital letter and end each item with a period or other terminal punctuation (e.g., !, ?), except when the bulleted items consist of short noun phrases or single words. In such cases, punctuate only the final bullet.
Generally, EERE prefers AP Style over Chicago Style on punctuating bulleted lists, except when AP Style end-punctuates each short phrase or single-word bullet. EERE makes an exception to this, preferring that short phrases and single-word bullets omit end punctuation, except for the final bullet. See lists.
Short phrases or single-word list punctuation
FOAs issued in the last three years:
- DE-FOA-
- DE-FOA-
- DE-FOA-.
Complete sentence punctuation
Use bulleted lists sparingly to:
- Highlight important items.
- Draw attention to main points.
- Help readers find information.
Do not use commas or semicolons at the end of bullets.
Incorrect
In response to the President's executive order, we are:
- Investing in supply-chain research and development,
- Soliciting advice from private industry, and
- Accelerating the development of new energy-storage technologies.
Use numbered or lettered lists instead of bullets if you want to refer to items in a list or procedure elsewhere in the text.
Steps needed to execute the order include:
- Request the form.
- Identify the target.
- Complete the form, including all boxes.
- Obtain PA approval of request.
Concerning Step 2, consult the database to identify the target accurately, including all descriptors.
Formatting. In text, the first level of bullet is indented 0.25 in., and text begins at the 0.5-in. mark. Each subsequent level of bullet is sequentially indented 0.5 in. In lists of items that are more than one line, each bulleted item is followed by a 6-pt. space.
Web content. Except for the indenting and spacing formats for reports, all the above guidelines apply.
A Cascading Style Sheet (CSS) governs web content on energy.gov. Web coordinators should check that the bulleted paragraph type they use has the correct spacing, as the energy.gov style does allow some flexibility. When formatting bullets on the website, there should be a space between the text above the bullets and the first bullet. To help facilitate scanning, consider a space between each bulleted item when the bulleted text is long.
Proper names. These include government programs, official projects, formal groups, organizations, companies, titles when they precede a name (use lowercase in titles that follow the name), specific geographic areas or features, and ethnic groups.
For companies and products with stylized lowercase or 'camel cap' names (e.g., iPod), use the company's or product's preferred capitalization.
Sandia National Laboratories
American Wind Energy Association
President and Chief Executive Officer Christine Johnson; Christine Johnson, president and chief executive officer
the Southwest
Lake Powell
the Colorado River
African, Asian, Caucasian, Hispanic, or Native Americans
Taxonomic names. For botanical and zoological divisions, capitalize the names of all divisions higher than species: genera, families, orders, classes, and phyla. Put genera, species, and varieties in italics. Spell out at first mention and then abbreviate after.
Clostridium thermocellum (first mention)
C. thermocellum (subsequent)
Escherichia coli (first mention)
E. coli (subsequent)
Headings, table titles, figure titles, and captions. Capitalize the main words of table titles and most headings and subheadings, including the second word in a hyphenated term. Verbs, including 'is' and 'are,' are always capitalized, including the word "to" in their infinitive form.
Do not capitalize articles (a, an, the); conjunctions (and, or, nor, but) less than five letters (e.g., for, of, to, from) unless they begin the title or heading.
Exception: If the heading takes up multiple lines, and the article or preposition comes at the beginning of a line, capitalize the article or preposition. (Applies mainly to printed products, as headlines on digital platforms may adjust automatically.)
PV Program Five-Year Plan
Table 1. Number and Frequency of Defects in Six Samples
Development of Method To Detect Anomalies
U.S. Department of Energy Announces Tribal Grant Relief Due to COVID-19
Even Equal Pay Day Is Not Equal
Prize Helps To Advance Awareness About Electronic Waste
Capitalize only the first word and proper nouns in figure captions.
Figure 1. Results for the electrochromic window
Results for E. coli
Follow the style recommended by your professional society or journal publisher regarding 'figure' and its abbreviation (Fig.) when you prepare a paper or an article for submission. Many societies and publishers recommend lowercasing everything but the first word and proper nouns in table titles, subheads, and captions.
States. Capitalize the names of states but capitalize "state" only when it appears with an official name, such as Kansas State Legislature. On second reference, state is never capitalized; however, Legislature is.
Capitalize "legislature" when preceded by the name of a state: the Kansas Legislature. Retain capitalization when the state name is dropped but the reference is specifically to that state's legislature.
the state of Colorado
Washington state
The forecast does not apply to the states below the Mason-Dixon line.
The Pennsylvania State University (Penn State)
The Washington State Legislature is winding up; both houses of the Legislature adjourned today.
Titles (professional). Capitalize titles when they precede the person's name. Lowercase titles and names of groups when they follow the name.
Former or future titles are also capitalized when preceding the person's name. Except for 'Acting,' which EERE prefers to capitalize, lowercase qualifiers (e.g., former, deposed, presumed).
See academic degrees to learn more about tiles for education levels.
The Secretary of Energy was appointed in .
Secretary of Energy John Doe attended the conference.
John Doe, the current secretary of energy, previously served as the deputy secretary of energy.
Chief Operating Officer Mark Wilson
Mark Wilson, the chief operating officer
former Secretary of State Henry Kissinger
Acting Chief of Police Robert Hand
John Doe, Ph.D., received his doctoral degree in physics in .
Dr. Jane Smith, M.D., received her medical degree from University of Somewhere in after obtaining a master's degree in chemistry.
Titles (composition). Titles of books, movies, plays, poems, albums, songs, operas, radio and television programs, lectures, speeches, and works of art. Capitalize all words in a title except articles (a, an, the); prepositions of four or fewer letters (for, of, on, up); and conjunctions of four or fewer letters (and, but, for, nor, or, so, yet) unless any of those start or end the title.
Gone with the Wind
Applied Physics Letters
The Denver Post
Science
Trade names. Commonly used government-owned trademarks should use the trademark notice symbols. Include the symbol in first use in heading and in body text; thereafter, omit the symbol.
Capitalize trade or brand names for third-party trade names (Kleenex, Pyrex). Do not use trademark notice symbols with third-party products or services.
Refer to the company's literature or stationery if you're not sure. See also the online database of current trademarks.
Common government-owned names and symbols
BUILD4SCALE'
Energy Earthshots'
EnergyPlus®
ENERGY STAR®
H2@SCALE'
Home Energy Score'
HydroGEN Advancing Water Splitting Materials'
RACE TO ZERO'
RAPID TOOLKIT®
Solar Decathlon®
SOLSMART®
Use a comma to separate items in a series, including the next-to-last word in the series (also known as the serial comma). EERE prefers Chicago Style over AP Style on this issue.
We develop solar thermal, wind, biomass, and photovoltaic energy technologies.
Comma placement is key in resolving ambiguity. Consider: "We will strengthen U.S. leadership by developing public-private partnerships, technology and interconnection standards, and the dissemination of high-quality market data." Should a comma follow "technology"? Does it mean "technology standards" and "interconnection standards"? Or are "technology and interconnection standards" one entity?
Use a comma to separate the parts of a compound sentence linked by a coordinating conjunction (and, but, or, nor) when each part has its own subject and verb (unless they're very short).
I laughed at the unintentional joke, but she frowned.
Use commas to set off nonessential or nonrestrictive words, phrases, and clauses from the rest of the sentence. The commas signal that the information between them is something extra and not essential to the sentence meaning.
The subsystem, which takes a day to install, will be delivered in two weeks.
Do not use commas to set off restrictive words or phrases that are essential to the sentence meaning.
Only the sensors that were attached to the outer edge failed. (essential phrase)
The system will work efficiently only if it includes storage. (essential phrase)
See also which and that.
Use commas to enclose the state name when it follows a city and the year when it follows the month and day.
The test systems in Gardner, Massachusetts, are performing well.
The next test sites will be in Golden, Colorado, and Chapel Hill, North Carolina.
On April 11, , the committee members completed five of the six objectives.
Do not use a comma to separate compound subjects or compound verbs.
Theorists and nonspecialists alike agree on the importance of the discovery. (No comma between the two parts of the compound subject.)
The researchers rolled out the thin metal sheet and formed it into coils. (No comma between the two parts of the compound verb.)
Verb phrases (verb, noun, and adjective forms). Verb phrases that contain an adverb (build up, set up, start up, break down) are usually written as two words. The noun and adjective forms of these words are either one word (no hyphen) or a hyphenated form of the words. However, there are exceptions. Refer to the dictionary for the correct spelling.
We observed the slow buildup of biofouling on the blades.
We helped with the setup.
The startup costs were higher than we estimated.
I think I'm having another breakdown.
Compound modifiers with and without hyphens. Use a hyphen to indicate that words have been combined into a compound modifier'a descriptive expression of two or more words that form one new meaning. For example, in the term 'flat-plate collector,' 'flat-plate' is the compound modifier.
low-level radiation
last-minute addition
fatigue-induced wear
five-year plan
nine-story building
ground-source heat pump
Although modern writing often eliminates hyphens, they help prevent ambiguity. To see how adding the hyphen can prevent confusion, consider: 'The scientists tested a new defect causing gas,' versus 'The scientists tested a new defect-causing gas.' In the first example, the scientists might seem to have been testing a defect; in the second example, it's clear that they have tested a gas.
See hyphens to learn more about what terms need no hyphens.
Compound words containing prefixes and suffixes. No hyphen is needed between many prefixes and suffixes and the root words, unless the root word is a proper noun.
Use a hyphen if the word that follows is a proper noun, or is capitalized, e.g., pre-Civil War.
Use two hyphens to join double prefixes, e.g., sub-sub-paragraph.
Prefixes that usually require a hyphen include "ex," "self," and "quasi." See hyphens.
Compound words containing prefixes and suffixes that don't need a hyphen:
multidimensional
multiyear
reevaluated
reuse
threefold, hundredfold (but 100-fold)
subassembly
prescreening
postdoctoral
retroactive
nonspecialist
No hyphen is needed between many prefixes and suffixes and the root words, unless the root word is a proper noun. See compound modifiers. Use a hyphen between prefixes and proper nouns (but not common nouns) or dates, whether they're used as nouns or modifiers.
non-EERE
mid-s
trans-American
pre-Civil War
No hyphen
nonprofit
prescreening
reuse
Use a hyphen for clarity or to prevent confusion. Consider: "The scientists tested a new defect causing gas," versus "The scientists tested a new defect-causing gas."
In the first example, the scientists might seem to have been testing a defect; in the second example, it's clear that they have tested a gas.
See compound words and modifiers.
Use two hyphens when adding a prefix to a word that already contains a prefix, even when there is no hyphen after the prefix in the original word.
non-self-limiting
sub-sub-head
Don't use a hyphen in common unit modifiers that are not ambiguous or confusing.
high school students
solar radiation resource
solar thermal electric systems
renewable energy future
cold climate heat pump technology
Don't use a hyphen when multiple words of a compound modifier are capitalized.
Bronze Age tools
Biofuels Program objectives
Nobel Peace Prize nomination
Don't use a hyphen with a compound modifier containing an adverb ending in '-ly.'
highly efficient motor
frequently missed deadlines
heavily skewed results
Omit hyphens if a sentence is rewritten so that the compound modifier comes after the noun it describes.
We purchased state-of-the-art lab equipment.
We purchased lab equipment that reflects the state of the art.
They made some last-minute adjustments.
They made some adjustments at the last minute.
When numbers are used in modifiers, retain all the necessary hyphens, or rewrite the sentence to omit the hyphens.
Numbers with modifiers and hyphens
2-ft.-diameter pipes
13-cm-wide substrate
Numbers with modifiers but without hyphens
pipes that are 2 ft. in diameter
a substrate that is 13 cm wide
Use a hyphen if the prefix ends in a vowel and the word that follows begins with the same vowel.
co-op
intra-arterial
co-occur
anti-immune
Exceptions
cooperate, coordinate, and double-e combinations such as preestablish, preeminent, preeclampsia, preempt
Units of measurement and mathematical expressions. Use numerals with units of measurement and time. Also see time, dates, percent, and addresses.
2-1/2 hours
4.5 months
36 cm
87 years
6 liters
25 kW
Use numerals to imply arithmetical values or manipulation.
a factor of 3
multiplied by 2
a ratio of 4:5
values of 1 and 48
Express measurement errors as: 6 nm ± 0.2 nm. Leave a space between the number and the unit of measurement (0.2 nm) and put spaces around the operation sign; when the measurement error appears by itself, omit the space between the sign and the number.
6 nm ± 0.2 nm
The measurement error is ±0.2 nm.
Time. With units of time, spell out numbers less than 10 consistently (applies to outreach communications products, not technical reports and papers).
five-year plan
two-hour test
three-week turnaround
30 minutes
five seconds
Aligning numbers. Align numbers with a common measurement unit by decimals inside a table column. Put a zero before the decimal in numbers smaller than one.
If all the numbers in a column do not share the same measurement unit, center the numbers in the column and specify the measurement unit. See data in tables.
Fractions and decimals. Spell and hyphenate simple fractions or express them (more complex fractions) in numerals with a slash.
one-fifth or 1/5
1/64 (but not 1/64th)
Use a hyphen to separate the integral and fractional parts of a mixed number or, convert the fraction to a decimal.
2-1/2 cm in diameter
2.5-cm-diameter solar cell
For numbers of 1 million or more, use the numeral (and a decimal, if necessary) and the words million, billion, etc.
1.1 million households
3.5 billion people
$2.5 million in funding
Precision and numbers. Decimalization should not exceed two places in textual material unless there are special circumstances, e.g., measurement uncertainly analysis, which calls for measurement precision to a significant digit to the right of a decimal point, such as two or three digits (hundredths or thousandths). Check with an expert before changing the number of digits to the right of the decimal or rounding the numbers. For amounts less than 1, use the numeral zero before the decimal point. See also standard errors.
Energy reduction per pole in this area was 59.3% compared to the QMH lighting system.
0.96
Punctuating numbers. Use a comma to separate groups of three digits in numbers.
5,182
113,728
2,225,000
Ranges of numbers. Use an en dash (which is shorter than an em or long dash) with no spaces. If the word "of" or "from" occurs before the range, then use the word "to."
To express a range between some number and another number, always use "and" with "between."
Note that some symbols, e.g., º and %, are repeated in a range.
15%'25%
6'12 cm
10'20 m2
from 32º to 40ºC
from 66 to 80 V
between 8 and 12 m (not "between 8 to 12 m")
$3 million'$4 million
Scientific notation. Express multiples of SI (metric) units in powers of 10 with the prefix and technical abbreviations.
mm (millimeters, 10-3 m)
MJ (megajoules, 106 J)
Spelling out numbers. Except with units of measurement and time, spell out numbers less than 10. EERE prefers "more than" to "over" to indicate greater numerical value. See units of measurement, time.
eight experimental runs
three species of yeast
Salaries went up more than $20 a week. (preferred)
Salaries went up over $20 a week.
Spell out all numbers at the beginning of a sentence.
Fifteen trials later, the results were the same.
Thirty-five participants attended the seminar.
When a sentence contains one or more numbers greater than nine that are related to a smaller number, use numerals for all of them.
The results were the same in 3, 12, and 18 trials.
The contractor tested 8 devices in May, 12 in June, and 9 in July.
Spell out the first of two adjacent numbers unless the first one requires three or more words. See also fractions.
ten 5-kW arrays
thirty-two 4-cm2 devices
135 16-cm collectors
Use quotation marks for direct quotes and the titles of articles. Use 'curly' or 'fancy' quotation marks instead of inch marks ("). In Microsoft Word, go to Insert --> Symbols --> Left (or Right) Double Quotation Mark.
Place commas (and periods) inside quotation marks; place semicolons, question marks, dashes, and exclamation points outside quotation marks unless they're part of the quotation.
Use single quotation marks to indicate a quotation within material already enclosed in double quotation marks.
"Let's meet again in six months," the chairman said, "to discuss our progress."
She presented a paper, "Materials Research in Silvered Polymer Reflectors."
"The results are in," he said.
"Can you hear me?" she asked.
Did he really say, "I don't believe you"?
'Explain what you mean by 'confidence,'" she said.
Block quotations. When quotations are longer than two or three lines, begin them on the next line and indent them on each side. No quotation marks are needed around block quotations. Use standard double quotation marks for quotes within block quotations.
The history of earthquake science began in the late 19th century, as described by Chris Jones, below.
The modern concept of earthquake mechanisms began in the s, when G.K. Gilbert, an American geologist, theorized that earthquakes were the result of displacement along geological faults (Gilbert ). In , H.F. Reid suggested that earthquakes were the result of a phenomenon called "elastic rebound", based on observations of the great San Francisco earthquake (Reid ). This theory states that an earthquake is generated by a rupture or sudden displacement along a fault strained beyond its elastic strength.*
* Chris Jones, History of the Science of Earthquakes, GPO, Washington, D.C., .
With in-text quotations, place reference numbers, superscripts, and author-date citations outside quotation marks. Place them after the final punctuation of the last sentence in a block quotation.
"EIA forecasts renewable penetration to reach 38 percent and 17 GW of energy storage capacity will be added to the U.S. electric grid by ."1
See footnotes, references and citations.
References cited must be used to credit the original source of a claim, quote, statistic, or data. This allow others to place the work in the context of the published literature and lend credibility to published work.
A complete citation source is required [author, year, title, and hyperlink, at a minimum]. Always add a URL if one exists, followed by a period, to the end of the reference. If space is tight, you can shorten the number of authors to "et al." after three. Place works consulted (but not cited in the text) in a bibliography.
For all EERE technical publications, consistently use in-text citations (with references at the end) or footnotes. EERE prefers in-text author-date references over numbered footnotes or endnotes, following Chicago Manual of Style formatting. To prepare a manuscript for a publisher other than EERE, follow that publisher's preferred reference style.
All EERE-funded reports are required to include an attribution to the sponsoring program at the program or subprogram level. This means that articles or reports funded by EERE through a financial assistance award (such as a grant or cooperative agreement), including national labs or other third parties, must include the appropriate Publication Acknowledgement Statement.
See footnotes.
In-Text Citations
Several experts (Wendt et al. ; McLing et al. ) have given a detailed description of RTES reservoir configuration, heat source requirements, heat recovery power cycle configuration, and operating principles.1,2
Footnote Citations
Several experts have given a detailed description of RTES reservoir configuration, heat source requirements, heat recovery power cycle configuration, and operating principles.1,2,3
Author-Date References
Wendt, D., H. Huang, G. Zhu, P. Sharan, K. Kitz, S. Green, J. McLennan, J. McTigue, and G. Neupane. . Flexible Geothermal Power Generation utilizing Geologic Thermal Energy Storage: Seedling Project Final Report. Idaho National Laboratory Technical Report. INL/EXT-19-. URL.
McLing T. L., D. Wendt, P. Dobson, C. Doughty, N. Spycher, D. Roberson, and J. McLaughlin. . Dynamic Earth Energy Storage: Terawatt-Year, Grid-Scale Energy Storage Using Planet Earth as a Thermal Battery (GeoTES): Seedling Project Final Report. Idaho National Laboratory Technical Report. INL/EXT-19-. URL.
Footnote References
1 Smith, J., J. Doe, T. Welsh, et al. . "Title Capitalized Regardless of Publication Capitalization." Journal Name Volume(Issue): page'page. URL.
2 Author. . Webpage or Article Title Capitalized. Publisher. Date Published or Accessed in EERE style format. URL.
3 Author. . Report Title in Italics and Capitalized. City, State/Country: Publisher Name. Publication number. URL.
Semicolons indicate a stronger or more important break in the flow of words than a comma.
Use semicolons in compound sentences (those with more than one subject and more than one verb) without conjunctions. When clauses in a sentence are closely related in meaning, a semicolon is an appropriate dividing punctuation mark. Note that the words "and," "but," "or," and "nor" do not follow semicolons.
It was difficult to reproduce the experiment; the material Smith and Jones used was not widely available.
Of the 13 samples, only one did not degrade; others deteriorated an average of 8%.
Use semicolons with conjunctive adverbs, except "yet" and "so," which are usually preceded by commas in a complex sentence. Use a semicolon before such conjunctive adverbs as "then," "however," "thus," "therefore," "hence," "accordingly," "moreover," "nevertheless," "consequently," "besides," "indeed," and "subsequently"; place a comma after the adverb. Use a semicolon before "i.e." ("that is") and "e.g." ("for example") and a comma after them when a clause (with a subject and verb) follows them; use a comma when a phrase or list follows.
Before conjunctive adverbs
We used the Schartz-Metterklume method in the experiment; however, the problems with this method are well known.
Energy requirements are often expressed in quads, or quadrillion Btu; therefore, this report describes the number of quads supplied annually by each option.
Exception: so
The contractor's representative was out, so I left a message.
Before e.g.,
Bring any two items; e.g., sleeping bags and tents are in short supply.
Use semicolons in a series. When items in a series contain internal punctuation (e.g., commas) or are very long, separate them with semicolons. In those cases, a conjunction can follow the last semicolon.
Internal punctuation
The contaminants in the sample were TCE, 150 ppb; toluene, 220 ppb; and benzene, 265 ppb.
Promising new technologies demonstrated at the exposition included advanced wind turbines; polycrystalline, thick-film, and thin-film solar cells; fast-growing energy crops; and fuel cells.
Long series
The vendor assured us that the replacement parts were on order; that the parts would be delivered as soon as they arrived; and that the delay in shipment was unavoidable.
States. In text, consistently spell out states' names rather than using U.S. Postal Service abbreviations. A comma is needed between a city and a state name, and also after a state or country name, unless ending a sentence.
D.C. may be used for the District of Columbia in text, in both formal and informal publications. When including addresses or state names in full addresses (containing streets and cities), contact lists, reference lists, and bibliographies, however, use the following postal abbreviations:
AL, AK, AZ, AR, CA, CO, CT, DC, DE, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY (PR, VI).
Note: EERE takes exception to AP Style, which never abbreviates eight states: Alaska, Hawaii, Idaho, Iowa, Maine, Ohio, Texas, and Utah.
California (rather than CA), Colorado (rather than CO), Wyoming (rather than WY)
He was traveling from Nashville, Tennessee, to Austin, Texas, en route to his home in Albuquerque, New Mexico.
She was born in Padua, Italy, in .
Always lowercase state or states, per typical common noun capitalization.
The residential building stock database contains modeled data on housing type and housing energy expenditures for each U.S. census tract, city, county, and state.
She lives in New York state.
The apples come from Washington state.
Countries. Do not abbreviate the names of countries (including the United States) when they are used as nouns. Use U.S. as the adjective form. See United States and U.S.
the United States
U.S. DOE program
U.S. population
Always lowercase country or countries, per typical common noun capitalization.
The average pool pump energy bill is probably higher in Florida than in many other areas of the country because of the long swimming season.
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