In strict analysis, abbreviations should not be confused with contractions, acronyms, or initialisms, with which they share some semantic and phonetic functions, though all four are connoted by the term “abbreviation” in loose parlance.
An abbreviation is a shortening by any method; a contraction is a reduction of size by the drawing together of the parts.
A contraction of a word is made by omitting certain letters or syllables and bringing together the first and last letters or elements; an abbreviation may be made by omitting certain portions from the interior or by cutting off a part. A contraction is an abbreviation, but an abbreviation is not necessarily a contraction.
Acronyms and initialisms are regarded as subsets of abbreviations (e.g. by the Council of Science Editors). They are abbreviations that consist of the initial letters or parts of words.
Abbreviations have a long history, used so that spelling out a whole word could be avoided. This might be done to save time and space, and also to provide secrecy. Shortened words were used and initial letters were commonly used to represent words in specific applications.
In classical Greece and Rome, the reduction of words to single letters was common. In Roman inscriptions, “Words were commonly abbreviated by using the initial letter or letters of words, and most inscriptions have at least one abbreviation.” However, “some could have more than one meaning, depending on their context. (For example, A can be an abbreviation for many words, such as ager, amicus, annus, as, Aulus, Aurelius, aurum and avus.)”
Abbreviations in English were frequently used from its earliest days. Manuscripts of copies of the old English poem Beowulf used many abbreviations, for example 7 or & for and, and y for since, so that “not much space is wasted”.
The standardisation of English in the 15th through 17th centuries included such a growth in the use of abbreviations. At first, abbreviations were sometimes represented with various suspension signs, not only periods. For example, sequences like ‹er› were replaced with ‹ɔ›, as in ‹mastɔ› for master and ‹exacɔbate› for exacerbate. While this may seem trivial, it was symptomatic of an attempt by people manually reproducing academic texts to reduce the copy time. An example from the Oxford University Register, 1503:
Mastɔ subwardenɔ y ɔmēde me to you. And wherɔ y wrot to you the last wyke that y trouyde itt good to differrɔ thelectionɔ ovɔ to quīdenaɔ tinitatis y have be thougħt me synɔ that itt woll be thenɔ a bowte mydsomɔ.
The Early Modern English period, between the 15th and 17th centuries, had abbreviations like ye for Þe, used for the word the: “hence, by later misunderstanding, Ye Olde Tea Shoppe.”
During the growth of philological linguistic theory in academic Britain, abbreviating became very fashionable. The use of abbreviation for the names of J. R. R. Tolkien and his friend C. S. Lewis, and other members of the Oxford literary group known as the Inklings, are sometimes cited as symptomatic of this. Likewise, a century earlier in Boston, a fad of abbreviation started that swept the United States, with the globally popular term OK generally credited as a remnant of its influence.
After World War II, the British greatly reduced the use of the full stop and other punctuation points after abbreviations in at least semi-formal writing, while the Americans more readily kept such use until more recently, and still maintain it more than Britons. The classic example, considered by their American counterparts quite curious, was the maintenance of the internal comma in a British organisation of secret agents called the “Special Operations, Executive”—”S.O.,E”—which is not found in histories written after about 1960.
But before that, many Britons were more scrupulous at maintaining the French form. In French, the period only follows an abbreviation if the last letter in the abbreviation is not the last letter of its antecedent: “M.” is the abbreviation for “monsieur” while “Mme” is that for “madame”. Like many other cross-channel linguistic acquisitions, many Britons readily took this up and followed this rule themselves, while the Americans took a simpler rule and applied it rigorously.
Over the years, however, the lack of convention in some style guides has made it difficult to determine which two-word abbreviations should be abbreviated with periods and which should not. The U.S. media tend to use periods in two-word abbreviations like United States (U.S.), but not personal computer (PC) or television (TV). Many British publications have gradually done away with the use of periods in abbreviations.
Minimization of punctuation in typewritten material became economically desirable in the 1960s and 1970s for the many users of carbon-film ribbons since a period or comma consumed the same length of non-reusable expensive ribbon as did a capital letter.
Widespread use of electronic communication through mobile phones and the Internet during the 1990s allowed for a marked rise in colloquial abbreviation. This was due largely to increasing popularity of textual communication services such as instant- and text messaging. SMS, for instance, supports message lengths of 160 characters at most (using the GSM 03.38 character set). This brevity gave rise to an informal abbreviation scheme sometimes called Textese, with which 10% or more of the words in a typical SMS message are abbreviated. More recently Twitter, a popular social networking service, began driving abbreviation use with 140 character message limits.