The RETAIN statement creates the variables FMTNAME and TYPE with fixed
values. The RETAIN statement is more efficient than an assignment statement
in this case. RETAIN retains the value of FMTNAME and TYPE in the program
data vector and eliminates the need for the value to be written on every iteration
of the DATA step. FMTNAME specifies the name of the format that the input
control data set creates. The TYPE variable specifies that the input control
data set will create a numeric format.
retain fmtname 'ptsfrmt' type 'n';