the DATA step contains a MODIFY statement, SAS writes the current
observation to its original place in the SAS data set. This action
occurs by default through an implied REPLACE statement at the bottom
of the DATA step.
However, you can override
this default behavior by explicitly adding the OUTPUT, REPLACE, or
General form for OUTPUT,
REPLACE, and REMOVE statements:
Here is an explanation of the syntax:
adds the current observation
to the end of the data set.
writes the current
observation to the same location in the data set.
removes the current
observation from the data set.
Using OUTPUT, REPLACE, or REMOVE ...