How to write and publish a scientific paper - Barbara Gastel, Robert A. Day 2022

Good practice
How and when to use abbreviations
Scientific style

It can be advisable, when writing the first draft of the manuscript, to spell out all terms and phrases in every instance. Then examine the text for repetition of long words or phrases that might be candidates for abbreviation. Do not abbreviate a term or phrase that is used only once or twice in the paper. If the term or phrase is used with modest frequency—for example, between three and six times—and a standard abbreviation for it exists, introduce and use the abbreviation. (Some journals allow some standard abbreviations to be used without definition at first use.) If no standard abbreviation exists, do not manufacture one unless the term or phrase is used very frequently or is very long and cumbersome.

Often, you can avoid abbreviations by using the appropriate pronoun (it, they, them) if the antecedent is clear. Another possibility is to use a substitute expression such as “the inhibitor,” “the substrate,” “the drug,” “the enzyme,” or “the acid.”

Usually, you should introduce your abbreviations one by one, as they first occur in the text. Alternatively, you might consider a separate paragraph (headed “Abbreviations Used”) in the introduction or in the materials and methods section. The latter system (required in some journals) is especially useful if the names of related reagents, such as a group of organic chemicals, are to be used in abbreviated form later in the paper. Another option, such as in review papers and grant proposals, can be to include a table that lists and defines abbreviations. Such tables make definitions easy to find even if a piece is not being read from beginning to end. Also, if chapters of a book might be read individually or in different orders, consider defining abbreviations on first appearance in each chapter. The same principle holds for other lengthy pieces of writing, such as long proposals, that might well be read other than from start to finish.