See also: A General List of Abbreviations

Abbreviations in technical publications are generally used in parenthetical and bracketed expressions, tables, figures, footnotes, and bibliographies. It is best to avoid abbreviations in running text although a few, such as i.e., e.g., viz., AD, BC, BP, and Ma, are permissible. The style of the text is followed in legends, tables of contents, and indexes. If the abbreviation of a term is new or may not be recognized, it is wise to write it in full the first time, with the abbreviated form in parentheses immediately following. Thereafter the abbreviated form may be used by itself.

Abbreviations should not be used at the beginning of a sentence.

Several types of construction resemble abbreviations. These include 'contractions' (e.g. can't), which are abbreviations that end with the last letter of the word abbreviated (e.g. Dr.), and 'clipped forms of words' (e.g. 'phone). Many abbreviations that are actually clipped forms of words are now accepted and are spelled without any apostrophe, for example, bus (omnibus), cello (violoncello), taxi and cab (taximeter cabriolet), and zoo (zoological gardens). Other constructions are 'acronyms', 'initialisms', and 'scientific terms' (weights and measures [metric and imperial symbols] and chemical symbols).

A list of abbreviations, including other constructions, has been prepared to help you. Approved SI symbols (not abbreviations) appear in the section entitled 'The International System of Units (SI)', popularly referred to as the metric system.

In recent years, there has been a marked trend toward the deletion of periods from abbreviations for scientific and engineering terms, particularly in tabular matter. When an abbreviation that takes a period comes at the end of the sentence, do not add another period; one performs both functions.

Do not use periods with the following:

1. chemical symbols and mathematical abbreviations: H₂O, cos, log, Ca, Fe
   
2. SI symbols: L, m, km, Ma
   
3. abbreviations for points of the compass: NNW (an exception is for an address: 32 Street N.W.)
   
4. acronyms and initialisms: NATO, UNESCO, GSC, CIMM but U.S.A., N.W.T.
   
5. these Latin words (which are not abbreviations):
   via
   et
   finis
   par
   pro
   ad
   ex
   in
   per
   sic

The plurals of most abbreviations are formed by adding an s but not an apostrophe:

In GSC publications, however, some abbreviations remain the same in the plural as in the singular:

Note that symbols for metric units do not take an s in the plural:

An abbreviation is capitalized or hyphenated only if the unabbreviated word is capitalized or hyphenated:

The names of provinces, territories, and districts may be abbreviated in addresses when they follow the name of a city, town, village, or geographic feature. These abbreviations may be used in figures and tables where space is limited; however, in GSC publications, they are spelled out:

The following abbreviations are used officially for the names of provinces and territories of Canada. Postal symbols, however, do not use periods and are listed here in the third column:

Do not abbreviate the words County, Township, Fort, Mount, North, Point, Island, Port, and Saint when they are part of a proper name, unless the abbreviated form is used in the official name (official spellings can be found in provincial gazetteers and on the Internet at this URL: http://geonames.nrcan.gc.ca.

Latitude and longitude are never abbreviated where used alone or in ordinary text:

What is the latitude of section 3?

In technical publications and in lists where co-ordinates are given, the abbreviated forms are used:

Note that the abbreviations for latitude and longitude are not capitalized.

Compass directions are abbreviated as follows:

The abbreviations NE, NW, SE, SW, may be used to denote town and city divisions in literary text, but the words north, south, east, and west should always be spelled out.

In designating lands covered by Canada Lands Surveys, abbreviations of the following type may be used in the order shown:

Periods and spaces are omitted between the letters of acronyms and initialisms.

An acronym is a pronounceable word formed from the first letters of a series of words:

Acronyms also serve to identify commonly used terms, but only after these are defined:

An initialism is formed from the first letters of a series of words and may not be pronounceable:

Use upper case letters for acronyms and initialisms in their entirety, even if some of the component words are not normally capitalized. Acronyms (but not initialisms) formed from company names are an exception:

Note that the legal titles of corporate names should be used. Words such as Company, Corporation, Association, and Limited should not be abbreviated unless they appear in such form in the corporate name. Also, the ampersand (&) should not be used unless it is part of the official name.

On first use of an organization or program name, put the abbreviation in parentheses immediately following the spelled-out name as it can be used to substitute for the name throughout the text.

See also 'Abbreviations' in the 'Grammar' section.

The names of months are always spelled out in the text and in text footnotes, except when used in citations or references. They may be abbreviated in tabular matter and sidenotes. May, June, and July, however, should not be abbreviated:

The names of the days of the week should not be abbreviated, except in tables:

Where there is a reference in the text to a large subdivision of a publication (Volume, Number, Part, Book, Section, Chapter), or to a smaller section (Figure, Table, Plate), the word is capitalized and not abbreviated except when referring to a figure in parentheses. Such a word is always followed by a number:

The exception is in the figures of a paleontological plate, e.g. Plate 1, figures 1 to 3 or (Pl. 1, fig. 1-3).

Smaller subdivisions (paragraph, line, page) in the text are written in full, but are not capitalized except in main headings:

See 'Capitalization' in the 'Grammar' section for details.

In bibliographies, reference lists, tables, and figures in a plate, words referring to parts of a publication should be abbreviated as follows:

The word Figure in a legend or caption is not abbreviated:

The figure caption should be a normal sentence. The article can be omitted in the information that follows the figure number.