REF or Ref is a three-letter abbreviation that may refer to:
Reference, something that refers to something else
Referee, in sports
Reform Party, in politics
The Ref, a film
Row echelon form, a mathematical matrix construct
Rapid Equipping Force, a United States Army unit
Relative effectiveness factor, a measure of the power of an explosive
Ref, a pseudonym of Belgian comics artist René Follet
REF, A symbol that means bio-degradeable
Better don't be this abbreviation in single word since this may be too ambiguous.