Punctuation

New Hart's Rules: Handbook of Style for Writers and Editors by Robert Ritter (Oxford University Press) is a useful reference for questions on punctuation and other aspects of presenting text.

Although all technical writers should ensure that they understand the rules for using apostrophes correctly, this is not a stylistic decision. The rules are clear and unequivocal, and the Apostrophe Protection Society explains them on its website.

Spaces after full stops

Online discussions have shown that some writers feel strongly about this point. In traditional typesetting, the space between sentences was 1.5 times the space between words. Although two spaces were used to approximate this in typed documents, RSA (a qualification body for typing) does not specify this practice. Choice of font and publishing tool can affect the spacing between sentences. Many computer fonts provide the correct spacing after a full stop but some are known to have errors in their kerning tables. Double spaces confuse some justification algorithms, will be ignored when working in HTML and may be converted to single spaces by some publishing tools.

Most technical writers seem to prefer one space between sentences. This preference is supported by many sources, including The Chicago Manual of Style and the style guides of Microsoft, IBM, Sun and Apple. However, readers with dyslexia are said to find a larger space between sentences helpful. If using a single space results in sentences running together, there are three ways to increase the space between sentences:

• Use a different font.
• Use a wider space (for example, an em space).
• Add a second space.

The serial comma

Conjunctions like and and but are sometimes preceded by a comma. This is most commonly seen in lists of items. For example, I bought eggs, bacon, sausages, and bread. If the items are short and clear, as they are in this example, omitting the comma does not change the meaning. However, if the items in the list include the word and, the meaning can sometimes be ambiguous. For example, I would like to thank my parents, Joe and Mary. This might mean that the writer's parents are called Joe and Mary or it might refer to four separate people. Inserting a comma makes the second meaning clear: I would like to thank my parents, Joe, and Mary. For more complex content where there is a significant risk of confusion, many writers would change the word order and perhaps even use two sentences or a bulleted list to ensure clarity.

As the Oxford University Press retains the serial comma, the usage is also known as the Oxford comma. The Concise Oxford Companion to the English Language states:

(3) Commas are used to separate items in a list or sequence, as in cases already given. Usage varies as to the inclusion of a comma before and in the last item (bring a chair, a bottle of wine, and a good book). This practice is controversial and is known as the serial comma or Oxford comma, because it is part of the house style of Oxford University Press. It is often superfluous, and there are occasions when the sense requires it to be omitted, but on many occasions it serves to avoid ambiguity: These colours are available: red, green, yellow, and black and white as opposed to red, green, yellow and black and white.

"COMMA" Concise Oxford Companion to the English Language. Ed. Tom McArthur. Oxford University Press, 1998. Oxford Reference Online. Oxford University Press. Syndicated edition for Institute of Scientific and Technical Communicators. 2 July 2007

Abbreviations and initialisations

It is uncommon to use full stops in initialisations, so it's ISTC rather than I.S.T.C. This forms part of a trend in British English towards minimal punctuation, which has seen the disappearance of commas from the ends of lines in blocked-out addresses, full stops from the ends of headings, and apostrophes from terms such as the 1970s and PCs. Full stops are also disappearing from abbreviations, such as Mr, although they are still seen. There is a trend to use only one capital letter in acronyms (initialisations pronounced as words), such as Nato.

Most technical writers favour a clean and modern look, provided that it does not make the text harder to read or understand. Punctuation marks should be retained for organising clauses and sentences, although some technical writers avoid semi-colons.

Lists

The punctuation used in bulleted (which is spelled with one t like targeted) or numbered lists is a matter of choice. A common practice is to distinguish points that are complete sentences and points that complete the lead-in sentence. For the former, each point takes a concluding punctuation mark. For the latter, depending on house style, the last point may take a concluding punctuation mark (preceding points may take commas or semi-colons but this is becoming less common).

For example:

Kitchen appliances save time spent on domestic chores in many ways:

• Refrigerators reduce the need to shop frequently.
• Freezers extend the period between major shopping trips.
• Washing machines do the washing while a householder is otherwise engaged.
• Tumble dryers remove the need to wait for fine weather to dry clothes.
• Cookers have automatic programmes to have meals ready on a householder's return.

Common kitchen appliances include:

• Refrigerators
• Freezers
• Washing machines
• Tumble dryers
• Cookers.

Points that are complete sentences start with an upper case letter. Points that follow on from the lead-in sentence may start with an upper or lower case letter but the convention chosen should be applied consistently.

Units of measurement

Most British periodicals do not use a space between quantities and units, whereas most international standards require a space. Many writers prefer a thin space so that the quantity and unit are grouped and a non-breaking space avoids quantities becoming separated from their units (thin spaces are usually also non-breaking). Temperatures and computer storage values are sometimes excluded from the requirement for a space. Percentages are usually excluded and, strictly speaking, are not units.

The following table summarises some guidance from the British Standards Institution.

The Bureau International des Poids et Mesures (BIPM) publishes the SI brochure, now in its eighth edition. In addition, the National Physical Laboratory (NPL) publishes guidance on units of measurement and the American National Institute of Standards and Technology (NIST) publishes a Guide to SI Units (but the latter reflects American English and so metre is not spelled in accordance with international practice).

When abbreviating inches, in is clearer than ". The full word is more common in text (for example, a 42-inch screen) for this and other non-SI units.

Capitalisation

Capital letters have some specific roles. New Hart's Rules states:

Capital letters in English are used to punctuate sentences, to distinguish proper nouns from other words, for emphasis, and in headings and work titles. It is impossible to lay down absolute rules for all aspects of capitalisation;

Writers should be consistent within a document or a set of documents. They should ensure their approach enhances rather than impedes readability and comprehension. Most style guides prefer other typographical means of emphasising words.

The use of capital letters in headings has declined. Headings often take only a single initial capital (sometimes called sentence case). However, where headings take initial capitals on all major words (sometimes called title case or headline style):

• Articles, pronouns and conjunctions usually take no capital.
• Both parts of compound words usually take capitals (for example, Non-Functional Requirements).

Perhaps the most controversial use of capitals is in creating proper nouns. As we have seen, this is correct but it should only be applied to true proper nouns. Some technical documents are peppered with inappropriate initial capitals. Proper nouns identify specific instances of generic nouns. For example, the generic noun window does not take an initial capital but the name of a specific example does: the Change Name window. It can be argued that window becomes part of the proper noun in a named example (and should therefore take an initial capital) but the usage shown seems more common.

The initialisation of proper nouns sometimes declines as they become incorporated into the language and treated as generic nouns. For example, World Wide Web is a proper noun but many people now write website for the generic noun. As an aside, on a related term, the Internet is a proper noun but an intranet is a generic noun (except when used for a particular company's intranet, in which case an initial capital might be used).

Hyphens and dashes

Three lengths of 'rule' characters exist:

• Shortest is the hyphen, which is used to form compound words (for example, at point-blank range).
• Next is the en-rule (or en-dash), which is used without spaces to link elements (for example, 1939–45) and, sometimes, with spaces in place of the em-rule.
• Longest is the em-rule or (em-dash), which is used with or without spaces to separate elements (for example, Mary was late—there was no driver for the train).

The terms en-rule and em-rule derive from the width of the n and m characters but the difference in length between the characters (-, –, —) depends on the typeface.

A similar character is the mathematical minus sign used to show negative numbers. Although writers often use a hyphen in its place, it is a distinct character (usually between the en-rule and em-rule in length, –).

When compound words are formed, they tend to start as separate words which are then hyphenated and sometimes later turned into a single word. The speed at which single words are formed differs between regional variants of English. Hyphens are used less today than they once were (for example, web site or website but rarely web-site). The easiest way to be consistent is to choose one dictionary as your reference and then follow its preferences on hyphenation. However, as new terms evolve more quickly than established ones, it may be difficult to determine best practice for words with the same prefix. For example, Oxford lists email, showing e-mail as an alternative, but retains the hyphen in e-business and e-commerce. Some words may be more difficult to read without a hyphen (Oxford retains the hyphen in co-worker). Preferred variants are likely to change when new editions of dictionaries are published.

Some house styles avoid the en-rule to link ranges, using the word to instead. The concern is that the en-rule might be mistaken for a minus sign.

In some contexts, to implies up to but not including. Some writers use through to avoid this but others view that as an American convention. Ensure that the convention you choose is understood by your readers. You can add the word inclusive to clarify.

Numbers as words or numerals

Conventionally, low numbers are written in words and higher numbers in numerals. Thresholds vary but words are often used for zero to ten in technical content, numbers below 100 in non-technical content, and one to twelve in music. Numbers at the start of sentences are usually written in words, while numbers with units are written in numerals. Where text contains many numbers, different conventions may be adopted for different roles (for example, 50 one-inch screws or ten 2 cm screws). Whatever convention you adopt, it's better to be consistent when citing ranges (for example, avoid five–15).

Some writers prefer to use numerals for all numbers. This makes it easier to scan text for numbers, which stand out more as numerals. However, this may not always be the effect you seek in a descriptive text.

Jakob Nielsen has suggested that all numbers should be written in numerals on-screen but ISTC members disputed whether delivery medium should be the deciding factor.

Quotation marks

There are two aspects to the use of quotation marks:

• Double or single
• Sequence with other punctuation marks.

Pocket Fowler's Modern English Usage states:

1. The main use of quotation marks (also called inverted commas) is to indicate direct speech and quotations. In writing it is common to use double quotation marks (" "), and in printing practice varies between the double and single style (''). Single marks are commonly associated with British practice (as in the Oxford and Cambridge styles) and double marks with American practice (as in the Chicago style), but the distinction in usage is not always so clear-cut.
2. The main rules of practice in BrE [British English] follow, with indications of any variant practice in AmE [American English]: (a) In direct speech and quotations, the closing quotation mark normally comes after a final full stop: She said, 'I have something to ask you.' It should come after any other punctuation mark (such as an exclamation mark) which is part of the matter being quoted: They shouted, 'Watch out!' (the final full stop is omitted after an exclamation mark in this position) / Did I hear you say 'Go away!'?. (b) When the quoted speech is interrupted by a reporting verb such as say, shout, etc., the punctuation that divides the sentence is put inside the quotation marks: 'Go away,' he said, 'and don't ever come back.' (c) If a quoted word or phrase comes at the end of a sentence or coincides with a comma, the punctuation that belongs to the sentence as a whole is placed outside the quotation marks: What is a 'gigabyte'? / No one should 'follow a multitude to do evil', as the Scripture says. In AmE, however, it is usual to place quotation marks outside the sentence punctuation (and note the more characteristic double quotation marks): No one should "follow a multitude to do evil," as the Scripture says. (d) When a quotation occurs within a quotation, the inner quotation is put in double quotations marks if the main quotation is in single marks (or vice versa, especially in American practice): BrE 'Have you any idea,' he asked, 'what a "gigabyte" is?' / AmE "Have you any idea," he asked, "what a 'gigabyte' is?".

"quotation marks" Pocket Fowler's Modern English Usage. Ed. Robert Allen. Oxford University Press, 1999. Oxford Reference Online. Oxford University Press. Syndicated edition for Institute of Scientific and Technical Communicators. 11 June 2007

Note: Italics are often used in place of quotation marks to emphasise terms, such as gigabyte above.

Trademark symbols

There are two symbols related to trademarks: ® indicates that ownership has been registered and ™ indicates that ownership is claimed. Trademark owners use these symbols to protect their trademarks. Other parties using trademarks should identify their ownership, usually in the front matter of a document and, except in textbooks, on first use in the text. It is unnecessary to repeat the symbol on every use and doing so impairs readability.

Some companies make a global claim that trademarks are registered, and must be indicated as such, when they are only registered in certain territories. Writers should check this with their legal department.

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