Use of abbreviations rules

Legal abbreviations usually refers to law publications; bar associations and legal organizations; federal and state agencies, boards, commissions, and departments; legal terms; court rules; statutes; and electronic databases and legal services.

The following are some indicative rules:

General rules
Use no contractions or abbreviations in any place where there is room to print the words in full.
All legitimate words should be spelled out in full in text matter, but abbreviations are often needed in book work for footnotes and tables and in commercial work, where many brief forms and signs are used which are commonly understood and are as intelligible as words.

Certain special forms of printing such as market and stock reports, sporting news, price lists, directories, telephone directories, and the like make extensive use of abbreviations and signs. These abbreviations are of very limited use and often of only temporary life. They are not intelligible to general readers and should never be used outside the particular form of composition to which they pertain. De Vinne suggests that in the absence of printed authority (many of these abbreviations not appearing in the dictionary lists) every proofreader would do well to keep a manuscript book of unlisted abbreviations which he has to use repeatedly as a means of securing uniformity of form.

For general abbreviations it is recommended to use The Chicago Manual of Style or The Gregg Reference Manual. Both these books contain extensive chapters on proper form in using abbreviations, as well as the possessive and plural forms of abbreviations.