abbreviations: general guidelines

The use of abbreviations has gained greater acceptance as an increasing number of new products and organizations are identified by shorter and more easily recognizable word forms.

If you are in doubt about the correct abbreviation for a term, use the long form.

In using abbreviations, follow the general rules set out below.

Unfamiliar abbreviations

Abbreviations (shortened forms of full terms) may not be familiar to all readers. For clarity, write out the full term the first time you mention it, and put the abbreviation in parentheses after the name.

• Canadian Space Agency (CSA)
• Royal Ontario Museum (ROM)

Once you have given the abbreviation in parentheses, ensure that you use the same abbreviation elsewhere in your text to represent the word or words involved.

Well-known abbreviations

If the abbreviation is better known than the full term, you should write the abbreviation first and put the full name in brackets after it at first mention.

• UNESCO (United Nations Educational, Scientific and Cultural Organization)

Common abbreviations often in the news need not be spelled out if the full term is rarely used or is difficult to pronounce.

• RCMP (Royal Canadian Mounted Police)
• 3M (Minnesota Mining and Manufacturing Company)
• DNA (deoxyribonucleic acid)
• HIV (human immunodeficiency virus)

In addition, some standard abbreviations (such as i.e., AD, IQ, ESP, CBC and MP) do not have to be spelled out because they are well known and in many cases occur as dictionary entries.

Informal abbreviations

Many commonly used words that are actually abbreviations are now rarely regarded as such, including ad, fridge, phone, exam, memo, photo and math.

Most such words should be avoided in formal writing, although cello and bus are exceptions to this rule.

Abbreviations in tables or lists

If space is limited—for example, in a table or list—using just the abbreviation may be the better choice, but remember to explain it somewhere else in your document.