in a SAS data set has attributes such as name, type, length, format,
informat, label, and so on. These attributes enable you to identify
a variable as well as define to SAS how the variable can be used.
By using the DATASETS
procedure, you can assign, change, or remove certain attributes with
the MODIFY statement and subordinate statements. For example, using
MODIFY and subordinate statements enables you to perform the following
assign, change, or remove a format,
which changes how the values are written or displayed
assign, change, or remove labels
Note: You cannot use the MODIFY statement to modify fixed attributes ...