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

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.