6. Words

6.1 Abbreviations

There are two kinds of abbreviations that you may have to use in your writing, and the guidelines for these are somewhat different:

abbreviations for technical terms in your own field
standard abbreviations that are in common use in all kinds of scientific writing

Abbreviations for technical terms in your own field

Abbreviations are useful in that they allow you to avoid repeating long technical terms in your writing. However, you should note these points:

Abbreviations are always liable to misinterpretation: for example, AA could mean Alcoholics Anonymous, Automobile Association, amino acid or atomic absorption, depending on the context and reader. Therefore, in your text you should introduce any abbreviation in parenthesis after the full word or term the first time it appears.

A hypertext document with its corresponding text and hyperlinks is written in Hyper Text Markup Language (HTML) and is assigned a non line address called a Uniform Resource Locator (URL) ...
Several hundred identical integrated circuits (Ics) are simultaneously created on a thin wafer ...

If, later on in your work, you have not repeated the abbreviation for several pages, you should introduce it in the same way again, just in case the reader has forgotten what it refers to.
You should avoid putting abbreviations in the title of your work and in your abstract
Limit the number of abbreviations you use: too many can be annoying and confusing to your readers
Avoid giving a long list of abbreviations at the start of your work. If you have enough to justify making a list, it is best to put it at the end.

Standard abbreviations in common use

Some abbreviations do not need to be spelled out because they are universally recognised. These include:

units of measurement (standard metric units, SI units) when a number precedes the unit. When there is no number, you should use the full form. (See also Section 5.1 Writing Numbers)

25 ml 14 kg 10 m 230 km 38oC BUT a few millilitres

chemical elements and compounds
mathematical operations and symbols

Latin and Greek abbreviations

Some abbreviations which originate from Latin or Greek may not be known to your reader, so it is normally better to use the full English equivalent. Use of the full form of the word also helps the text to flow better for the reader. Some of these, though, are useful in your references and bibliography.

abbreviation	comment + meaning
c. / ca. / circa	use the English word: approximately, about
cf.	use the English word: compare
e.g.	normally better to use the English words: for example, for instance
et al.	use after authors' names in your bibliography, but avoid in your text (= and others)
etc.	try to avoid, as it implies lack of precision (= and so on, and the rest)
ibid	only use in your list of references (= in the same place, that is in the book you have just mentioned)
i.e.	normally better to use the English phrase: that is, in other words
loc. cit.	only use in your references (= in the place mentioned before)
NB	use the English word: Note
op. cit.	only use in your references (= in the book mentioned before)
q.v.	only use in your references (= see in another place, that is for a cross-reference
v. / vs.	use the English word: against, versus
viz.	use the English word: namely

Most used abbreviations cf. Essential Glossary of Abbreviations and Acronyms: