The Writer's Desk Book / Being a Reference Volume upon Questions of Punctuation, Capitalization, Spelling, Division of Words, Indention, Spacing, Italics, Abbreviations, Accents, Numerals, Faulty Diction, Letter Writing, Postal Regulations, Etc.

by William Dana Orcutt

THE PERIOD

Always place the period inside the quotation-marks and inside the parentheses when parenthetical matter forms an independent sentence and is not a part of the preceding sentence. {12}

Use the period:

1. After every abbreviation.

2. To set off decimal numbers from whole numbers.

3. After every complete sentence unless the sentence is interrogative or exclamatory.

4. To indicate an ellipsis, repeating the mark three or more times separated by spaces: e.g., . . .

Do not use the period:

1. After running-heads.

2. After cut-in side-notes.

3. After centered head-lines.

4. After box-heads in tables.

5. After legends beneath illustrations.

6. After subheads set in separate lines.

7. After date-lines at the top of letters.

8. After signatures at the end of letters.

9. At end of lines in display composition, such as titles,[2] blocked headings, etc.

10. After roman numerals, even though they possess the value of ordinals: e.g., Vol. VIII; George V is king of England.

[2] First adopted by William Pickering, the London publisher, about 1850.