MFD
An MFD is a multi-functional display, i.e. a display that can be used for different tasks at different times, combining the function of various instruments. Most Orbiter vessels are equipped with two of these; the basic (non-panel) cockpit view puts them at the bottom corners of the screen. Some vessels (such as the Dragonfly) have only one MFD.
MFD is a square computer display, emulating an LCD display with a set of pushbuttons arrayed around the screen to control various aspects of the mode running in the display. The display (MFD monitor) is in the center of the MFD with various buttons to each side and bottom. The bottom buttons from left to right are:
PWR, keyboard shortcut ShiftEsc turns the MFD on and off. The MFD in the glass cockpit may be turned off in order to see what's outside behind the MFD.
SEL, keyboard shortcut Shift+F1 lists all the MFD modes which have been activated in the launchpad module tab. Up to 12 MDF modes are displayed on each page. Selecting SEL multiple times will page through lists of modes, then back to the most recent active mode.
MNU, keyboard shortcut Shift+', will switch to a menu of the function buttons, listing a short description of each button on the main mode screen, press MNU will return the mode to the main display.
The keyboard shortcut is activated by pressing the left Shift key for the left MFD and the right Shift for the right MFD. Additional MFDs cannot use a keyboard shortcut, they must be controlled with the mouse.
Additional MFDs may be opened by selecting the Function button on the Orbiter main menu, then selecting External MFD from the Custom Function window. The External MFD will be displayed in a window which may be moved around on your screen, even to a second monitor.
The buttons on each side of the MFD display are used to controlling various aspects of the active MFD mode. Each button may be activated with a mouse-click, or may have a keyboard shortcut assigned by the developer, again using left shift for the left MFD and right shift for right MFD.
In Orbiter parlance, MFD has also come to mean a downloadable module which provides new functionality for the MFDs. Examples are TransX, IMFD (both for long-distance flight planning), AeroBrakeMFD (which allows accurate atmospheric maneuvres). In the Orbiter manual that comes with the Orbiter download, they are referred to as MFD modes. MFD modes supplied with the stock Orbiter 2016 include: