Mr. or Mr is an English honorific used for a man too old to be addressed as Master, under the rank of knighthood, and, supposedly, though not really in practice, above some undefined level of social status (see below). In Britain, though not in the United States, the title also excludes those who have the title Dr. It is an abbreviation (or contraction) of Mister, though it is almost never spelt

In the United States, a full stop (period) almost always follows the abbreviated form of mister, in line with the standard practice of American English. In most Commonwealth countries and in Ireland, however, "Mr" is considered a contraction (as it includes the final letter of the original word), and therefore no full stop is used.

Origin

Mister is an alteration of Master; the equivalent female titles, Mrs, Miss, and Ms, are variants of Mistress. After the development of the word Mister for adult males, the title Master was retained and used for boys and young men.

Usage

When addressing someone directly, Mr is usually used with the last name only ("May I help you, Mr Ericson?"). In other circumstances, it can be used with either the last name or the full name ("This is Mr James Ericson."; "Would you please help Mr Ericson?"). On envelopes, it is usually used with the full name, or with initials and surname.

The title of Mr, like any other title, is a term of respect, and failure to use it where it might be expected may be interpreted as a sign of (perhaps deliberate) disrespect, though it is commonly not used among close friends or in other familiar settings.

The title "mister" is sometimes used informally by itself in direct address ("Are you all right, mister?"). In formal and military usage, the title sir is used ("May I help you, sir?").

Honorifics are properly used only to refer to others, not oneself. To identify oneself, it should suffice to say "This is John Smith," or if the first name is irrelevant, "My name is Smith."

Etiquette

Historically, Mr, like Sir, indicated an ill-defined social status only applied to gentlemen or persons above one's own station as a mark of respect. This understanding is all but obsolete today.

In past centuries, Mr. was used with a first name to distinguish among family members who might otherwise be confused in conversation: Mr. Smith would be the oldest present; younger brothers or cousins were then referred to as Mr. James Smith, Mr. Robert Smith and so on. Such usage survives in family-owned business or when domestic servants are referring to adult male family members with the same surname: Mr. Robert and Mr. Richard will be out this evening, but Mr. Edward is dining in. Such usage is rare.

In the Southern United States, Mr. is sometimes used with only the first name to indicate a mixture of familiarity and respect. Children are frequently encouraged to use this locution when referring to and addressing adult friends of the family.