AAO-MQ	Australian Astronomical Optics - Macquarie University
A&G camera	Acquisition and Guiding camera, see description of instrument subsystems
AESOP	Australian-European Southern Observatory Positioner, see description of instrument subsystems
AHM	All Hands Meeting
AIP	Leibniz-Institut für Astrophysik Potsdam, lead institute of the 4MOST Consortium
AIT	Assembly, Integration, Test
AL2	Additional L2 Data
APOGEE	Apache Point Observatory Galactic Evolution Experiment
CaCW	Cassegrain Cable Wrap
CASU	Cambridge Astronomical Survey Unit
CCB	Configuration Control Board
CfLoI	Call for Letters of Intent
CfP	Call for Proposals
CIS	Cassegrain Installation Stand
CMM	Coordinate Measuring Machine
CoC	Code of Conduct
COG	Centre of Gravity
Consortium	The 4MOST Consortium is the group of institutes responsible for designing and building the 4MOST Facility, and for operating the instrument jointly with ESO
CRS	Cosmology Redshift Survey, one of the 4MOST Consortium Surveys, see description of Extragalactic Surveys
DL2	Deliverable L2 Data
DMS	Data Management System, 4MOST system that will reduce, analyse, validate, and publish all data
DS	DocuShare
DXU	Data eXchange Unit, format for a given 4MOST data product, see description of data products
eROSITA	extended ROentgen Survey with an Imaging Telescope Array, an X-ray imaging instrument to be launched in 2019, which will perform an all-sky survey
ESA	European Space Agency
ESD	Electrostatic Discharge
ESO	European Southern Observatory, the organisation which owns and operates the VISTA telescope
ESPRESSO	Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations
ETC	Exposure Time Calculator
Euclid	An optical/near-infrared space telescope to be launched by ESA in 2021
EXB	Executive Board
FCHW	Facility Control Hardware
FCSW	Facility Control Software
Fibre-hour	One hour of observing with one fibre
Field-of-View (FoV)	The size of the area on-sky that 4MOST can observe with one pointing
Figure-of-Merit (FoM)	A quantity describing how much progress a 4MOST survey has made towards meeting its requirements during operations
FP	Fibre Positioner
FROG	Fourmost operational Rehearsals Observational data Generator
Gaia	An ongoing ESA space mission designed to measure astrometry and photometry of more than one billion stars in the Milky Way. Gaia data will form the basis of the 4MOST Galactic Surveys' input catalogues.
GTO	Guaranteed Time Observations, in exchange for building 4MOST, the Consortium will receive 70% of the time available on 4MOST over the course of the five years
HRS	High Resolution Spectrograph, see description of instrument subsystems
ISO	International Standards Organisation
IWG	Infrastructure Working Group
JOG	Joint Operations Group
JSON	JavaScript Object Notation
L0, L1, L2	Different types of data products, see description of data products
LAR	Local Acceptance Review
LDLS	Laser-Driven Light Source
LoI	Letters of Intent, expression of interest by a member of the ESO community to propose for a Public Survey using 4MOST, see this description of the selection process for Community Surveys
LRS	Low Resolution Spectrograph, of which 4MOST will have two, see description of instrument subsystems
LSST	Large Synoptic Survey Telescope, an 8.4-m telescope currently under construction, with full operations scheduled for 2022. LSST will image the entire available sky every few nights for 10 years, in order to provide time-domain science.
MAIT	Manufacturing, Assembly, Integration and Test