Abbreviations, acronyms and numbers - simple things that most writers take for granted. That is, most writers do not feel that they need any special attention. However, in scientific writing, nothing should be taken for granted, and there are several considerations when including these things in your manuscript.

Abbreviations are shortened forms of a complete word, sometimes followed by a period but sometimes not. Some common abbreviations are:

Of course there are many other abbreviations, and their use is acceptable and often preferable. However, journals have varying rules for which abbreviations can be used without definition. It is vital that you check the journal's guidelines for accepted abbreviations. For example, some publications accept abbreviations for time (e.g. second, minute, hour, day) while others do not. Publications rarely accept abbreviations for months (e.g. Jan. for January) within the text of the manuscript; however, common abbreviations are accepted within figures and tables. (If they are not well-known, define them.) The word 'figure' often may be abbreviated as 'Fig.' However there are special rules for this usage. It is often abbreviated when it falls within parentheses, and it can only be abbreviated when followed by a number or numbers. When it is the first word of any sentence, 'Figure' must be spelled out, and picky journals will also require it to be spelled out at the beginning of the actual figure legend. Do not abbreviate units of measurement without a number; "Several ml. were added" is wrong. "Several milliliters were added" is correct.

Because 'Fig' is the most commonly misused abbreviation in scientific writing, it warrants its own examples:

Acronyms: Acronyms, or initialisms, are formed by the first letters of a group of words, sometimes pronounced as a word (e.g., ANOVA for analysis of variance) and sometimes not (e.g. MRI for magnetic resonance imaging). Again, it is essential that the instructions the publication gives to authors be followed exactly. Those instructions should include a list of acronyms that are accepted without definition. If you are a medical researcher and are submitting to a journal outside of your particular field of study, do not assume that this journal will accept the same acronyms as those within your field. Reviewers, referees, and editors find it annoying when these instructions are not followed, increasing the chances that your manuscript will not be accepted. It may also give them the impression that the manuscript has already been rejected by another publication, because they assume you are following some other journal's instructions. If a particular acronym is not listed by the journal, it must be defined at first instance. Here are examples of the incorrect and correct ways to define an acronym in a scientific journal:

In the abstract, it is best to avoid using unfamiliar acronyms because they will stil need to be defined at first instance there, and again at first instance in the body of the article. Simply spell out the term in full, unless it is used several times within the abstract.

Two important guidelines for acronyms:

1 - "When in doubt, spell it out."

2 - Check the journal's "Author's Instructions" for:

• Accepted abbreviations for units of measurement.
• Accepted acronyms that do not need defining.
• Use of acronyms in the article title and abstract.

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