Read GENERAL REMARKS of Punctuation‚ A Primer of Information about the Marks of Punctuation, free online book, by Frederick W. Hamilton, on

Book titles are now set without points. This fashion was introduced by Pickering of London about 1850. This method is generally to the advantage of the title page thus treated. It is possible, however, to carry it too far and so to obscure the sense. Commas should not be omitted from firm names, such as Longmans, Green & Co., as in case of such omission there is no way of knowing whether one or more persons are indicated. Punctuation should not be omitted from the titles which may accompany an author’s name, nor from the date if day and month are given as well as year.

Avoid the doubling of points wherever possible. When an abbreviation precedes a colon, omit the period. When an abbreviation precedes a comma, the period is often inserted, but in many cases one or the other can be dropped to advantage. The dash is not generally preceded by a comma, semicolon, or colon in current printing usage. A comma should rarely go before the first parenthesis. If used at all with the parentheses, it should follow the closing parenthesis. When a complete sentence is enclosed in parentheses, the period falls within the parentheses. When the enclosure is a brief passage at the end of a sentence, the period falls outside the parentheses.

Do not put a period before the apostrophe and the possessive s as in Co.’s. The word Company may be abbreviated to Co. although it is not desirable to do so if it can be avoided. The possessive of Co. is Co’s.