When the news reached his mother, she fainted.
Commas set off an explanatory phrase but not a restrictive phrase of inclusive qualification. One writes: Poe, a poet of America, wrote "The Raven." But one writes: Poe the poet is a finer craftsman than Poe the fiction writer.
Use commas before conjunctions in a sentence made up of separate clauses, each with its own subject nominative, as, The horse is old, but it is still willing. If the same subject, write it: The horse is old but willing.
Use no period after letters used in place of numbers, as, B Company. (Companies of soldiers are designated as B Company, not Company B.)
Use hyphen and no apostrophe when dates are joined, as, 1861-65.
Write the caliber of a revolver or rifle with a period, as .22.
Use no commas in years and street numbers, as, 1904, not 1,904; and 2452 High street. But write: 2,156 persons and $1,560.
Follow this style in date lines: CHICAGO, May 10.—
BROWNSVILLE, Mich., May 10.—
Avoid this form as hackneyed: His wealth (?) has disappeared.
Place a comma or a colon after said, remarked and similar words when quoted matter follows.