MD

**MD**, **Md**, **mD** or **md** may refer to:

MD, Md, mD, or .md commonly refers to a Markdown file in software development. A .md file is a plain text document written using Markdown syntax (like # Heading). It’s often used for README files and can be converted into HTML, PDF, or other formats using online tools such as Toflio.
## Places
* Moldova (ISO country code MD)
* Maryland (United States postal abbreviation MD)
* Magdeburg (vehicle plate prefix MD), a city in Germany
* Mödling District (vehicle plate prefix MD), in Lower Austria, Austria

## People
* Major Douglas (1879–1952), British Engineer and pioneer of the Social Credit economic reform movement
* Muhammad (name) or Mohammed (Md)

## Arts, entertainment, and media
### Music
* '** or **' (MD or m.d.), used in piano scores to mark sequences of notes that are to be played with the right hand
* MiniDisc, an optical storage medium developed by Sony
* Music director; the term "MD" is used particularly in musical theatre

### Other arts, entertainment, and media
* *MDs* (TV series), a 2002 made-for-television medical drama
* '**, ("Materials and discussions for the analysis of classical texts"), an Italian classics journal
* Mega Drive, a game console produced by Sega

## Brands and enterprises
* Air Madagascar (IATA airline code MD)
* McDonnell Douglas (aircraft model prefix MD), a former aerospace manufacturer that later merged with Boeing

## Science and technology
### Biology and medicine
* Doctor of Medicine (MD), from the Latin **'
* Medial dorsal nucleus, a large nucleus in the thalamus
* Muscular dystrophy, a genetic and hereditary muscle disease
* MD (Ayurveda), a degree in the Indian medical system of Ayurveda

### Computing
* .md, Internet top-level domain for Moldova
* Markdown (file extension .md), a format
* mdadm (multiple device), a device driver used to support RAID in the Linux kernel
* Message-digest algorithm, a cryptographic hashing function
* Microdrive, a type of miniature hard drive
* mkdir or md, an operating system command to create a directory

### Other uses in science and technology
* Mean absolute difference, a measure of statistical dispersion
* Mendelevium (Md), a chemical element
* Mesoscale discussion, a short-term technical meteorological forecast concerning convection; See Storm Prediction Center or Weather Prediction Center
* Methyldichloroarsine, a blister agent used in chemical warfare
* Millidarcy (mD), a unit of fluid permeability
* Molecular dynamics, a method of computer simulation of molecular interaction
* Membrane distillation, a process of membrane filtration
* Earthquake duration magnitude ()

## Other uses
* MD, 1500 in Roman numerals
* Majority decision, a winning criterion in several full-contact combat sports
* Man-day, amount of work performed by the average worker in one day
* Managing director, a chief executive
* Marque déposée (MD), an international trademarking symbol in countries where French is the dominant language; See Unicode subscripts and superscripts
* Match Director (MD), person who handles the overall match administration before, after and during an International Practical Shooting Confederation match
* Memorial Day

## Related pages
* Medium (disambiguation)