FALSE() returns the boolean constant FALSE and can be placed anywhere a boolean is expected. Its most important use is in
VLOOKUP as the range_lookup argument to enforce exact matching: =VLOOKUP(A2,table,col,FALSE()). Omitting this argument defaults to
TRUE (approximate match) which returns silently wrong results on unsorted data. In
IF formulas, FALSE() can be returned as the value_if_false when the formula needs to explicitly produce a boolean rather than a number or text. In COUNTIF, passing FALSE without quotes counts cells containing the boolean FALSE, while passing "FALSE" in quotes counts cells containing the text string FALSE — a meaningful difference when auditing imported data. When testing whether a cell contains the boolean FALSE, use =B2=FALSE() which distinguishes the boolean from the text string, identical to the approach used with TRUE().