9. Abbreviations and Letter Symbols
9.1.
Abbreviations and letter symbols are used to save space and to avoid distracting the reader by use of repetitious words or phrases.
9.2.
The nature of the publication governs the extent to which abbreviations are used. In text of technical and legal publications, and in parentheses, brackets, footnotes, sidenotes, tables, leaderwork, and bibliographies, many words are frequently abbreviated. Heads, legends, tables of contents, and indexes follow the style of the text.
9.3.
Internal and terminal punctuation in symbols represening units of measure are to be omitted to conform with practice adopted by scientific, technical, and industrial groups. Where omission of terminal punctuation causes confusion; e.g., the symbol in (inch) mistaken for the preposition in, the symbol should be spelled out.
9.4.
Standard and easily understood forms are preferable, and they should be uniform throughout a job. Abbreviations not generally known should be followed in the text by the spelled-out forms in parentheses the first time they occur; in tables and leaderwork such explanatory matter should be supplied in a footnote. As the printer cannot rewrite the copy, the author should supply these explanatory forms.
9.5.
In technical matter, symbols for units of measure should be used only with figures; similarly, many other abbreviations and symbols should not appear in isolation. For example, energy is measured in foot-pounds, not energy is measured in ft·lbs.
Capitals, hyphens, periods (points), and spacing
9.6.
In general, an abbreviation follows the capitalization and hyphenation of the word or words abbreviated. It is followed by a period unless otherwise indicated.
- c.o.d.
- St.
- but ft·lb
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