Abbreviations That Require Periods
Abbreviations
Rulebase Summary
Use periods with: initials for a person's name (with spaces between them), the abbreviation U.S. when said as an abbreviation, city abbreviations when said as abbreviations, A.M. and P.M., and B.C./A.D./B.C.E./A.C.E.
BGGP Abbreviation.11 · p.241 BGGP Abbreviation.12 · p.242 BGGP Abbreviation.13 · p.242 BGGP Abbreviation.14 · p.242
Examples
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A. I spoke with MP Jackson about the case.
✓
A. I spoke with M. P. Jackson about the case.
Initials for a person's name take periods and spaces.
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Q. Did you arrive before 3:00 PM?
✓
Q. Did you arrive before 3:00 P.M.?
A.M. and P.M. take periods.
Transcript Notes
The dictionary lists both A.M. and a.m. — the capitalized version is recommended to avoid the issue of having the lowercase version begin a sentence. If initials are used alone or it is not known what they stand for, still use periods and spaces.
Style Guide References (4)
BGGP
Abbreviation.11
Page 241
BGGP
Abbreviation.12
Page 242
BGGP
Abbreviation.13
Page 242
BGGP
Abbreviation.14
Page 242
See also (13)
Compare Abbreviations That Do Not Take Periods Related Single Period When a Sentence Ends with an Abbreviation Related Time — O'clock, A.M., and P.M. See No Spaces Between Letters of an Abbreviation (Except Name Initials) See Abbreviating and Capitalizing Titles with Names See Abbreviating Geographic Words in Proper Names (Saint, Mount, Port, Point, Fort) Related Periods and Lowercase for i.e. and e.g. Related Question Mark After a Sentence Ending with an Abbreviation Related Commas with Titles, Degrees, and Designations After Names Related Time — Hours, Minutes, and Military Time Compare Military Time Uses Four Digits With No Colon Related Capitalization of Abbreviations and Acronyms Compare Time Zone Abbreviations Only When Spoken as Abbreviations