The HPBIN Procedure
ID variables ;
The optional ID statement lists one or more variables from the input data set to be transferred to the output data set. The ID statement accepts both numeric and character variables. The variables in an ID statement can also appear in an INPUT statement.
To avoid data duplication for large data sets, the HPBIN procedure does not include any variables from the input data set in the output data set by default. Therefore, the ID statement can be used to copy variables from the input data set to the output data set.