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.
In addition to abbreviations in the strict sense (including the short forms of common nouns, Latin expressions and titles), this chapter contains information and recommendations regarding acronyms, initialisms, and symbols such as those for metric units, which are uniform in many languages.
Many abbreviations will not be understood unless the term is written in full at first mention, with the abbreviation given in parentheses. Follow these general rules:
In recent years there has been a trend toward the omission of periods in abbreviations. This is particularly true of scientific and technical writing, but the practice has been spreading in general writing as well.
(a) Do not use periods with the following:
(b) Use periods
If a sentence ends in an abbreviation taking a period, only one period is used.
For further information on spacing, see 7.02 Spacing.
Add an s, but not an apostrophe, to form the plural of most abbreviations:
Use an apostrophe and s to form the plural of numerical names of aircraft ending in a single letter:
In cases where the resulting form would be ambiguous, add an apostrophe before the s:
Add an apostrophe and s to form the plural of abbreviations containing more than one period, and an s without an apostrophe, to form the plural of abbreviations with only one period. In the latter case, the s precedes the period:
The plurals of Mr. and Mrs. are irregular:
The plural forms of the abbreviations for certain bibliographic references are different:
Note that SI/metric symbols maintain the same form for both singular and plural and are written without periods, except at the end of a sentence:
In general, an abbreviation is capitalized or hyphenated if the unabbreviated word or words are so treated:
When an abbreviation is formed from letters most or all of which are part of a single word, it is capitalized, even though the full term is not:
See 1.16 Acronyms and initialisms for rules governing the capitalization of acronyms and initialisms.
Use the following abbreviations for non-military titles preceding or following personal names:
Use Ms. when referring to a woman unless a preference for Mrs. has been indicated. Although not an abbreviation, Ms. is written with a period, by analogy with Mr. and Mrs. Note that Miss is not an abbreviation and does not take a period.
Do not use Mr., Mrs., Ms., Dr. or Esq. with any other abbreviated title or with an abbreviation denoting an academic degree or honour:
Do not use the abbreviation Dr. and Rev. Dr. before the names of individuals who hold only honorary doctorates.
Saint is written out for names of persons revered as holy, but may be abbreviated in informal contexts and in lists and tables:
St. and SS. (plural) are the abbreviations used.
Abbreviate professional and official titles only when they are used with surnames preceded by first names or initials:
Note that there are spaces between each period and the following initial or name.
Even when used to address someone in correspondence, Rt. Hon., Hon. and Rev. must be preceded by the:
The honorary title "the Honourable" is used before the names of members of the Canadian Privy Council, lieutenant-governors and certain other officials. The title "the Right Honourable" applies for life to the governor general, prime minister and chief justice of Canada. See Department of Canadian Heritage, Precedence of Canadian Dignitaries and Officials.
Do not abbreviate Mayor, Vice-President, Professor and Father when used with personal names.
In the following table, the middle column gives the abbreviations used by the Department of National Defence (DND) and the right-hand column those used in non-DND writing:
|Officers||DND writing||non-DND writing|
|Second Lieutenant||2Lt||2nd Lieut.|
|Officer Cadet||OCdt||(not abbreviated)|
|Other ranks||DND writing||non-DND writing|
|Chief Warrant Officer||CWO||(not abbreviated)|
|Master Warrant Officer||MWO||(not abbreviated)|
|Warrant Officer||WO||(not abbreviated)|
|Master Corporal||MCpl||(not abbreviated)|
|Navy||DND writing||non-DND writing|
|Commissioned Officer||Comm Offr||(not abbreviated)|
|Acting Sub-Lieutenant||A/SLt||(not abbreviated)|
|Naval Cadet||Nav Cdt||(not abbreviated)|
|Chief Petty Officer, |
|CPO 1||(not abbreviated)|
|Chief Petty Officer, |
|CPO 2||(not abbreviated)|
|Petty Officer, |
|PO 1||(not abbreviated)|
|Petty Officer, |
|PO 2||(not abbreviated)|
In non-DND writing, the plurals of these abbreviated titles are formed by adding s to the principal element:
Note that at the Department of National Defence, Ret is the abbreviation for Retired.
Give these and other distinctions in abbreviated form after the name of the bearer:
Unless all honours have to be indicated for information or protocol purposes, no more than two abbreviations need follow a person’s name—as, for example, in correspondence. Select the two highest honours of different types and list them in the followingorder of precedence: first, distinctions conferred directly by the Crown (VC, QC, etc.); second, university degrees; and third, letters denoting membership in societies and other distinctions. Note that no periods are used.
The names of provinces, territories and districts may be abbreviated when they follow the name of a city, town, village or geographical feature:
It is not necessary to use the provincial abbreviation after the names of well-known cities such as Vancouver, Winnipeg, Toronto, Ottawa and Fredericton. However, since the same name is often shared by several places in Canada and other parts of the English-speaking world (e.g. Perth, Windsor, Hamilton), add the appropriate abbreviation in cases where doubt could arise.
The following abbreviations are used officially for the names of provinces and territories in Canada. The right-hand column lists the two-character symbols recommended by Canada Post for use with mailing addresses. For other purposes, use the traditional provincial abbreviations:
|Newfoundland and Labrador||N.L.||NL|
|Prince Edward Island||P.E.I.||PE|
A territory known as Nunavut was established under the Statutes of Canada, Bill C-132, assented to on June 10, 1993. The Act came into force on April 1, 1999. Nunavut consists of the eastern part of the Northwest Territories. Although the traditional abbreviation has not yet been officially established, the Translation Bureau recommends Nun.
Do not abbreviate words such as County, Fort, Mount, North, Point, Island, Port and Saint used as part of a proper noun, unless the official name for the location shows the abbreviated form:
For further information on the official form of geographical names, see Chapter 15 Geographical Names.
Words such as Street, Avenue, Place, Road, Square, Boulevard, Terrace, Drive, Court and Building are spelled out in general writing but may be abbreviated in footnotes, endnotes, sidenotes, tables and addresses. If the word forms part of a longer name, do not abbreviate it under any circumstances:
Abbreviate compass directions as follows:
In general writing, the abbreviations NE, NW, SE and SW may be used to denote town and city divisions, but the words north, south, east and west should always be spelled out:
In general writing, abbreviated compass directions in street addresses are followed by a period:
On pieces of mail, abbreviated compass directions are not followed by a period.
Do not abbreviate words such as East, West, Southeast, Northwest when they appear before a street name:
Do not abbreviate the words latitude and longitude when used alone or in ordinary prose:
In technical work and when lists of co-ordinates are given, use the abbreviations lat. and long.:
Capitalize, but do not abbreviate, parts of a document when followed by a number or letter, e.g. Part 4, Table 14, Appendix C.
Smaller subdivisions such as paragraph, line, page and verse are also written in full but are not capitalized except in main headings. See 4.30 Parts of a book or document for further treatment of these points.
In footnotes, endnotes, bibliographies and indexes, words referring to parts of a publication should, in the interest of conciseness, be abbreviated:
Beware of confusing and misusing the following abbreviations:
Note that the following Latin terms are not abbreviations and are never followed by a period unless they are placed at the end of a sentence:
There is a vast array of technical and scientific abbreviations such as those for mathematical ratios and operations, physical quantities and constants or statistical formulas and notations. Most unabridged dictionaries list such abbreviations. People working in specific disciplines should consult the appropriate manuals in their field.1
In biology, the Latin name for a genus is not abbreviated if used alone. When used with the species name, it is abbreviated as of the second reference. The species name is not abbreviated:
In symbols for chemical elements, compounds and formulas, use subscript, not superscript, numerals, e.g. H2SO4, SO2.
The following is a list of terms often abbreviated in the names of companies or business corporations. The abbreviated forms may be freely used in footnotes, tables or bibliographic references. Avoid using Assoc., Bros., Co. and Corp. within the body of your text. Inc. and Ltd., however, may be used unless it is necessary to preserve the company’s full legal title:
An acronym is a pronounceable word formed from the first letters of a series of other words, such as NAFTA, NATO or GATT. An initialism is formed from the initial letters of a series of words and may not be pronounceable as a word. Examples are GST, RCMP, OECD and IDRC. The distinction is a fine one and is often overlooked in practice. Do not use periods or spacing between the letters of an acronym or initialism.
In general, acronyms are not preceded by the definite article:
Usage varies with respect to initialisms. Those representing the names of organizations generally take the definite article, while those representing a substance, method or condition do not:
The correct form of the indefinite article (a or an) to use before acronyms and initialisms is determined by the consonant or vowel sound of the initial syllable, letter or number. The following examples illustrate correct English usage. Note that ease of pronunciation is the key:
Use upper-case letters for acronyms or initialisms in their entirety, even if some of the component words or their parts are not normally capitalized—unless the organization concerned prefers lower case:
Acronyms (not initialisms) of company names formed by using more than the initial letters of the words they represent. Usually, only the first letter of the acronym is capitalized:
Initialisms are always fully capitalized:
Common-noun acronyms treated as fullfledged words, such as radar, laser, scuba and snafu, are written entirely in lower case without periods.
When using acronyms or initialisms such as SIN (social insurance number), PIN (personal identification number) or ISBN (International Standard Book Number) do not repeat the word number (e.g. "SIN number"). Either write the expression out in full or use the abbreviated form on its own.
When abbreviating the words number or numbers within the body of a text, use No. or Nos. but not the symbol #, which is generally reserved for tabular and statistical material:
Use the percent sign (%) in economic, financial, statistical or other documents where figures are abundant. In material of a general nature containing isolated references to percentages, the term is usually written out, except when used adjectivally:
The ampersand (&) is properly used only when it forms part of a corporate name:
Do not use the ampersand in federal department legal or applied titles:
When it is necessary to distinguish dollar amounts in one currency from those in another, use the appropriate symbol with the figure in question:
Always spell out the names of the months in the body of your text and in footnotes. They may be abbreviated in tabular matter, citations and references, forms and sidenotes. May, however, should not be abbreviated and June and July are shortened only in military writing.
The names of the days of the week are not abbreviated, except in tables.
Present exact time as follows:
For elapsed time, use colons, periods and no spaces:
See 5.12 Representation of time in ordinary prose and with SI units and 5.13 Representation of time of day for additional information.
Time zones are abbreviated when used with a specific time. Note that capitals are used, without periods. Otherwise they are written out in full:
The International System of Units (SI), which has replaced other metric systems and is now used in Canada and many other countries, is a decimal-based system that includes units for physical quantities.
There are seven base units in SI:
|amount of substance||mole||mol|
In addition, a number of derived units are used. Like the kelvin and the ampere, almost all of them are named after scientists associated with a scientific discovery. Thus, when the symbol is used, its initial letter is capitalized. When written in full, however, the unit name is in lower case, e.g. H for henry and F for farad.
Celsius takes an initial capital whether written in full or as a symbol.
The table below gives a complete list of derived units:
|coulomb||C||quantity of electricity, electric charge|
|degree Celsius||°C||Celsius temperature3|
|gray||Gy||absorbed dose of ionizing radiation|
|joule||J||energy, work, quantity of heat|
|sievert||Sv||dose equivalent of ionizing radiation|
|tesla||T||magnetic flux density|
|volt||V||electric potential, potential difference, electromotive force|
|watt||W||power, radiant flux|
Multiples and submultiples of base units and derived units are expressed by adding one of the prefixes from the following table directly to the unit name:
The prefix and unit name are always spelled as one word:
When symbols are used, the prefix symbol and unit symbol are run together:
Leave a full space between the quantity and the symbol:
For the sake of clarity, a hyphen may be inserted between a numeral and a symbol used adjectivally (see also 2.10 Numerals and units of measurement):
Unit symbols and prefixes should always be in lower case, even when the rest of the text is in upper case:
The symbol L for litre (to distinguish it from the numeral 1) and, as mentioned above, those symbols derived from the names of scientists.
SI usage prescribes that both numeral and unit name be written in full or that both be abbreviated:
Current usage, however, accepts the use of numerals with spelled-out unit names to facilitate comprehension:
In scientific and technical writing, the preferred form is numerals with unit symbols:
When no specific figure is stated, write the unit name in full:
Area and volume in the metric system are expressed by means of superscript numerals:
Do not use abbreviations such as cc or cu. cm for cubic centimetre (cm3), kilo for kilogram (kg), amp for ampere (A) or kph for kilometres per hour (km/h).
Because of their practical importance, the following additional units are approved for use with SI, although they do not, strictly speaking, form part of it:
|mass||metric ton, tonne||t|
Note that there is no standard symbol for week or month. These units should therefore always be spelled out in technical writing.
When a unit symbol is combined with a symbol for time, or with a derived unit implying a division, an oblique (/) separates the two:
More detailed information on the International System of Units (SI) can be found in the National Standard of Canada, Canadian Metric Practice Guide (CAN/CSA-Z234.1-89).
Abbreviations for imperial weights and measures take the same form for singular and plural. Area and volume in this system are usually expressed by means of the abbreviations sq. and cu. rather than a superscript numeral. Leave a space between sq. or cu. and the abbreviation that follows it:
Terms are often abbreviated for the purpose of conserving space in routine business correspondence. The following are common abbreviations used in tables and on business forms:
The following is a list of symbols for terms used in business correspondence and in tabular and statistical material:
Note that a space is usually required before and after the symbols @, =, & and ×:
No extra space is required for upper-case abbreviations or in e-mail addresses:
Note also that no space is required between figures and the symbols %, ¢, #, ’, ’’:
Do not leave any space after the symbols $, #, ¶, § when they precede a figure:
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