Abbreviations and punctuation
An abbreviation of a single word requires a period at the end.
Mrs.
Jr.
Corp.
Esq.
Organization names and products
When the abbreviation appears in the names of organizations and products, the period is occasionally omitted by the company itself. Always follow the lead of the organization/manufacturer.
Small-letter abbreviations
Almost all small-letter abbreviations made up of single initials require a period after each initial, but no space after each internal period.
a.m.
p.m.
i.e.
e.g.
Abbreviating two or more words
If an abbreviation of two or more words consists of more than single initials, insert a period and a space after each element in the abbreviation.
Lt. Col.
Rt. Rev.
Slang terms
Slang terms are not abbreviations and should not be followed by a period except at the end of a sentence.
End of sentence punctuation
No space should follow an abbreviation at the end of a question or exclamation. Insert the exclamation point or question mark directly after the period. Do not omit the period that is part of the abbreviation.
If an abbreviation ends with a period, that period also serves to mark the end of the sentence. Do not use a double period.
T: The patient was instructed to apply topical antibiotic cream to the affected area t.i.d..
E: The patient was instructed to apply topical antibiotic cream to the affected area t.i.d.
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