TCMOS – Abbreviations – Chapter 10

Sunday, January 12, 2020
Blog #10 of my learning from #TheChicagoManualOfStyle.

A short topic today. Abbreviations.

Definitions

Acronym: Short forms based on initial letters and read as single word. Ex: AIDS, NASA, Scuba.

Initialism: Terms read as series of letters. Ex: IRS, NBA

Contractions: Include first and last initial. Mr. Amt.

Usage

Chicago recommends spelling out abbreviations unless present in a tables, bibliographies, and parenthetical references.

Format

1. Use periods for abbreviations that end in lowercase letter. E.g., a.k.a., a.m., p.m., Ms., Dr., vol.
2. Initials within a name take periods unless the entire name is abbreviated. JFK takes no periods, but J. K. Rowling does.
3. Abbreviation containing more than two capital letters takes no periods too: PhD, VP, SAFe
4. British and French omit periods from contractions like Dr, etc.
5. Certain abbreviations have a slash instead like c/o, n/a.
6. Initialisms tend to be all caps. LCD, UNICEF, NAFTA
7. A or an is determined by the first sound.  An HMO. A NATO member.
8. The US Military omits periods and capitalizes their ranks. But traditional form differs as follows: CPT or Capt.
9. Civil titles: Asst. Prof.
10. Academic titles: MS is same as master of science. Note the case.
11. Media companies are all caps with no periods. ABC NBC MTV WTTW
12. For United States and its states, spell out except for DC (especially when a state follows a city, spell). In a table, bibliography, and mailing addresses, they are abbreviated with postal code. Following is the difference between postal code abbreviation and traditional: FL vs Fla. GU vs Guam OK vs Okla. Same rule applies to Canadian provinces.
13. No comma between postal code (of state) and zip code.
14. United States should be spelled out in the noun form, but a US athlete is acceptable in the adjective form.
15. Compass directions are caps with no period. NE, NW.
16. Spell out months unless space restrictions where they would be abbreviated as follows: Jan. May. Dec. Sept.
17. Spell out days of the week unless space restrictions. Mon. Tues. Sat. Follow these in formal prose, in a table, drop the period.
18. Time zones are capitalized with no period. EST
19. The US units are identical in singular and plural form. 10 yd. 5 lb.

My Takeaway

Please refer to the Chicago Manual of Style for a complete list of abbreviations broken by category. My takeaway from this chapter is the presence or omission of a period based on the case of the abbreviation (rule 1-3 above).

Next week, also down to the basics. We’ll learn about parts of a book. Chapter 1.

Source: The Chicago Manual of Style, SEVENTEEN EDITION.

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