Style guide

a, an the use of a or an before an initialism depends on the pronunciation of the first letter of the initialism use a before initialisms beginning with b, c, d, g, j, k, p, q, t, u, v, w, y, or z use an before initialisms beginning with a, e, f, h, i, l, m, n, o, r, s, or x see also acronym and initialism abbreviation a shortened form of a word, such as qty (quantity) or in. (inch), or an acronym or initialism form plural acronyms or initialisms by adding a lower-case ‘s’ at the end, ex. PSUs do not add ‘s’ if the abbreviation is being defined at first use by the plural form of its full term, ex. Power Supply Units (PSU) see GSM terms and abbreviations or WCDMA abbreviations see also acronym and initialism absorbent not -ant acronym a word formed from the initial letter or letters of each of the successive parts or main parts of a compound term, ex. AIDS, laser, radar see GSM terms and abbreviations or WCDMA abbreviations see also abbreviation and initialism AC power not AC mains, AC mains power, AC mains power supply, AC mains power supply voltage, AC power supply, mains AC power, mains AC power supply, mains power, or mains see also power and power supply (unit) A/D see analog-to-digital adaptation not adaption add-on (adj. and noun, hyphen); to add on (phrasal verb, two words) adjustable plier wrench not pliers

adverbs do not use hyphens after adverbs ending in -ly, for example, a hotly disputed penalty, a constantly evolving newspaper, genetically modified food, and so on; but hyphens are needed with short and common adverbs, for example, ill-prepared report, hard-bitten hack [G] affect, effect exhortations in the style guide had no effect (noun) on the number of mistakes; the level of mistakes was not affected (verb) by exhortations in the style guide; we hope to effect (verb) a change in this [G] air condition (two words) air condition/, -ed, -er, -ing air duct (two words) airflow (one word) but air flows in airflows airtime (one word) ex. airtime slots alligator clip (US) UK (2G) use crocodile clip

alphanumeric (one word) alternate (adj.) every other or every second one also synonym for alternative in US, ex. an alternate plan, but use alternative aluminium (UK) aluminum (US) ammeter not amp meter or ampere meter see also clamp-on ammeter among not amongst analog-to-digital (attributive, hyphens) ex. analog-to-digital conversion, but converted from analog to digital (no hyphens) antenna pl. -s; not antennae, which only animals possess anti-clockwise (UK, hyphen) US (3G) use counterclockwise (one word) antistatic (one word) any more (two words) apostrophe the apostrophe is not normally allowed in CPI, so the guidelines below are for non-CPI writing use the asterisk (*) key on middle row of the keyboard (immediately to the right of Ä) not the accent key (´) on the top row (immediately to the right of the ? key) Some plural nouns have no ‘s’, for example, children. These take an apostrophe and ‘s’ in the possessive, for example, children’s games (never childrens’, as in section 51.1 of CSM 2003), gentlemen’s outfitter, old folk’s home.

The possessive in words and names ending in ‘s’ normally takes an apostrophe followed by a second ‘s’ (Jones’s, James’s), but be guided by pronunciation and use the plural apostrophe where it helps: Mephistopheles’ rather than Mephistopheles’s.

Use apostrophes in phrases such as in two days’ time, 12 years’ imprisonment and six weeks’ holiday, where the time period (two days) modifies a noun (time), but not in nine months pregnant or three weeks old, where the time period is adverbial (modifying an adjective such as pregnant or old).

If in doubt, test with a singular such as one day’s time, one month pregnant.

And if anyone tries to tell you that apostrophes don’t matter and we’d be better off without them, consider these four phrases (listed in Steven Pinker’s The Language Instinct), each of which means something completely different: my sister’s friend’s investments my sisters’ friends’ investments my sisters’ friend’s investments my sister’s friends’ investments [G] appendix pl. appendices for the supplement, appendixes for the anatomical organ Apple > CLICK < Change your life!

appropriate use correct or relevant, depending on context approximately use about authorize not -ise autoconfiguration autoconfigure autonegotiation (one word) auxiliary not -llawl pointed tool for marking surfaces or piercing small holes, especially in leather or wood axis pl. axes AXX (not an initialism) a type of cross-connector azimuth horizontal direction expressed as the angular distance between the direction of a fixed point (as the observerâ&#x20AC;&#x2122;s heading) and the direction of the object (not azimuth angle, angle of azimuth, or similar)

1 observer, 2 zenith, 3 star, 4 meridian, 5 vertical circle, 6 azimuth, 7 horizon