Acronyms should generally be spelled out the first time they appear in a book, as in: “Computer Development Environment (CDE).” After the acronym has been defined, you should generally use the acronym only (not the whole term, unless it makes more sense contextually to use the whole term). Usually, acronyms are defined only once per book. But if you prefer, you can also define them the first time they appear in each chapter.

A.M. and P.M. or a.m. and p.m.—be consistent.

K = 1,024; k = 1,000. So a 56 kbps modem is equal to 56,000 bps, while 64K of memory is equal to 65,536.

In units of measure, do not use a hyphen. For example, it’s 32 MB hard drive, not 32-MB hard drive. (Though when the unit is spelled out, use a hyphen, e.g., 32-megabyte hard drive.)

University degrees (e.g., B.A., B.S., M.A., M.S., Ph.D., etc.) can appear with or without periods—just be consistent.

Use chapter number only for references in a chapter.

An example of a chapter cross-reference: see Chapter 27.

An example of a section cross-reference: see the section “Treatment”. (The text “on page x” will be added post-conversion, so the final xref will eventually read “see the section “Treatment” on page 37.”)

An example of a section cross-reference in another chapter: see “Acceptable Gifts” in Chapter 27.

These cross-reference styles are also available in DocBook under various <xref> formats. Please refer to https://prod.oreilly.com/external/tools/docbook/docs/authoring/ (username: guest; leave the password blank).

Spell out numbers under 10, unless the same object appears in a sentence with an object 10 or over (five apples; 5 apples and 100 oranges).

In most numbers of one thousand or more, commas should be used between groups of three digits, counting from the right (32,904 not 32904). Exceptions: page numbers, addresses, port numbers, etc.

Use numerals for versions (version 5 or v5).

You may use a numeral if it’s an actual value (e.g., 5% 7″ $6.00).

32-bit integer.

1980s or ’80s.

Phone numbers can appear in the format xxx-xxx-xxxx.

Use an en dash (–) with negative numbers or for minus signs, rather than a hyphen.

Figure 1-1. Figure captions are initial-capped on first word only, with the exception of proper nouns. There is no period after figure captions, but if all captions are long and sentence style, periods can be used as long as they are used consistently throughout.

Table 1-1. Column heads and table titles are initial-capped on the first word only, with the exception of proper nouns. There is no period after table titles.

Example 1-1. Example titles are initial-capped on the first word only, with the exception of proper nouns. There is no period after example titles.

In most of our design templates, A- and B-level headings are cap and lowercase: cap the first letter of each word, with the exception of articles, conjunctions, and program names or technical words that are always lowercase and coordinating conjunctions (e.g., “and,” “but,” “for,” etc). Prepositions of four letters or less are not initial-capped, unless they function as part of a verb (e.g., “Set Up Your Operating System”). Hyphenated words in subordinating conjunctions (e.g., “as,” “if,” “that,” “because,” etc.) are always initial-capped (even if they are four letters or less). Hyphenated words in titles or captions should both be capped if the second word is a main word, but only the first should be capped if the second word isn’t too important (it’s a bit of a judgment call). For example: Big-Endian, Built-in. See The Chicago Manual of Style.

C-level headings have initial cap on the first word only, with the exception of proper nouns and the first word that follows a colon (unless that word refers to code and should be lowercase).

D-level headings (rare) are run-in with the following paragraph and have an initial cap on the first word only, with the exception of proper nouns and the first word that follows a colon (unless that word refers to code and should be lowercase), with a period at the end of the heading.

Don’t use “they” for third-person singular; alternate between “he” and “she.”

Do not use a hyphen between an adverb and the word it modifies. So, “incredibly wide table” rather than “incredibly-wide table.”

Unless part of a proper noun, close up words with the prefixes “multi,” “pseudo,” “non,” and “sub” (e.g., “multiusers,” “pseudoattribute,” “nonprogammer,” and “subprocess”).

Avoid using the possessive case for singular nouns ending in “s,” if possible. So, it’s “the Windows Start menu,” not “Windows’s Start menu.”

Avoid wholesale changes to the author’s voice—for example, changing the first-person plural (the royal “we”) to the first-person singular or the second person. However, do try to maintain a consistency within sentences or paragraphs, where appropriate.

Companies are always singular. So, for example, “Apple emphasizes the value of aesthetics in its product line. Consequently, it dominates the digital-music market” is correct. “Apple emphasize the value of aesthetics in their product line. They dominate the digital-music market” is not . (Also applies to generic terms “organization,” “team,” “group,” etc.)

When referring to software elements or labels, always capitalize words that are capitalized on screen. Put quotes around any multiword element names that are lowercase on screen and would thus be hard to distinguish from the rest of the text (e.g., Click “Don’t select object until rendered” only if necessary.)

Use “between” for two items, “among” for three or more. Use “each other” for two, “one another” for three or more.

Serial comma (this, that, and the other).

Curly quotes and apostrophes (“ ” not " ") in regular text.

Straight quotes (" " not “ ”) in constant-width text and all code. Some Unix commands use backticks (`), which must be preserved.

No period after list items unless one item forms a complete sentence (then use periods for all items within that list, even fragments).

Lowercase the first letter after a colon: this is how we do it. (Exception: headings.)

The Chicago Manual style (15th Edition) is our default.