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)

### 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

### 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 <samp>md</samp>, 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)