History

The Oxford English Dictionary (first edition) says that 'm' is sometimes a vowel in words like spasm and in the suffix -ism. In modern terminology this would be described as a syllabic consonant — IPA .

Meanings for M

• In archeology, M is an abbreviation for "Authentic Matthew"

• In astronomy, M is an abbreviation for "Messier" in designations for the Messier Deepsky Objects.

• In biochemistry, M is the symbol for methionine.

• In calendars, M is often an abbreviation for Monday or for one of the months "March" or "May".

• In chemistry,
• *M is the symbol for molarity (M) of solutions.
• *m is the symbol for molality (m) of solutions.

• In the CMYK color model, M stands for the color magenta.

• In comic books, M is the name of a member of "Generation X", a team of younger mutants affiliated with and coached by some of the former "X-Men".

• In computing,
• * M is a binary prefix meaning 2²⁰ = 1,048,576 (cf M as a Metric prefix below).
• * M is another name for the computer programming language MUMPS.
• In common references to currency, M or m denotes million or millions, such as $25M (twenty-five million dollars).
• In traditional accounting practice, M designates thousand or thousands, and MM is used for million. Hence such traditional abbreviations as CPM for cost per thousand items of a retail good, or MCF for thousand cubic feet of (e.g.) natural gas.
• In film,
• *M is the name of a film from 1931 directed by Fritz Lang about a serial killer who preys on children; see M (1931 movie).
• *M is the name of a lesser-known film from 1951; see M (1951 movie).
• *In the James Bond books and films, M is the codename of the head of MI6; see M (James Bond).
• In international licence plate codes, M stands for Malta.
• In mathematics, m is used to denote slope in slope-intercept form. An M-set is the opposite of a set of uniqueness.
• In the Metric system,
• *M, mega, is an SI prefix denoting 10⁶ = 1,000,000 (one million) (cf. M in computing above)
• *m, milli, an SI prefix meaning 1/1000.
• *m denotes metre (or meter), the SI base unit for length.
• In music,
• *M is the assumed name of the artist Robin Scott, who performed the 1979 #1 hit song "Pop Muzik".
• *-M- is the artist name of the French singer Matthieu Chédid.
• *"M" is the pseudonym for a Jazz vocalist hired by Yoko Kanno (see M (singer))
• In physics, M-theory is a proposed solution for problems in superstring theories.
• As the first letter of a postal code,
• * In Canada, M stands for the Metropolitan Toronto area.
• * In the United Kingdom, M stands for Manchester.
• In radiocommunication, M is one of the ITU prefixes allocated to the United Kingdom.
• In Roman naming convention, M is the abbreviation for the praenomen Marcus, and M' stands for Manius.
• In Roman numerals, M denotes one thousand, from mille in Latin.
• In video games,
• *M is the ESRB rating symbol for Mature.
• *M is the abbreviation for Mario, a Nintendo character.
• *The name of a glitch Pokémon, called 'M. (The real name consists of a glitchy symbol before and after the 'M.)
• M is an abbreviation for the Russian design bureau Myasishchev
• In economics, M is usually used to represent imports.
• In photography, most SLR cameras use M to signify manual mode, where the user sets both aperture and shutter speed.
  

  Alternate representations

  Mike represents the letter M in the NATO phonetic alphabet.

In Braille the letter M is represented as ⠍ (in Unicode), the dot pattern:
XX .. X.

Computing

The ASCII code for capital M is 77 and for lowercase m is 109; or in binary 01001101 and 01101101, correspondingly.

The EBCDIC code for capital M is 212 and for lowercase m is 148.

The numeric character references in HTML and XML are "M" and "m" for upper and lower case respectively.

See also