The terms 4to, 8vo, 12mo, etc., used to denote the sizes of books, are not abbreviations, and so do not take periods after them. Each number stands for a suppressed part of the word in which it appears.
The abbreviations i. e., e. g., vs., viz., etc., are often printed in italics. The words for which they stand are generally preferred to the abbreviations.
THE APOSTROPHE
There are but few uses of the apostrophe, and they are well settled, as follows:
1. To indicate the omission of letters or figures in contractions: ne’er, don’t, it’s (it is), ’t will, class of ’83, the gold-seekers of ’49, etc.
2. To indicate the possessive case of nouns, but not of pronouns: Henry’s, man’s, Jones’s, a boy’s task, the boys’ play-ground, for conscience’ sake, etc.
3. To indicate, with s, the plurals of letters, figures, symbols, and certain unusual or peculiar names: i’s and t’s, 6’s and 7’s, four t’s, several D.D’s, the stay-at-home’s, etc.
WHEREAS—RESOLVED
In the absence of a better place to note the conventional form of printing and punctuating the above words and what follows them, we consider the subject here. Two illustrations are sufficient to show the best usage. We prefer the first style. The second is that of the Century Dictionary, and is good style:
130A. Whereas, Our neighbors have suffered great loss ...