The UNIVARIATE Procedure

The ID statement specifies one or more variables to include in the table of extreme observations. The corresponding values of the ID variables appear beside the n largest and n smallest observations, where n is the value of the NEXTROBS= option in the PROC UNIVARIATE statement. See Example 3.3.

If you specify the IDOUT option in the PROC UNIVARIATE statement, ID variables are included in the output data set that is created by an OUTPUT statement.