The VARIOGRAM Procedure
ID Statement
ID variable ;
The ID statement specifies which variable to include for identification of the observations in the OUTPAIR= and the OUTACWEIGHTS= output data sets. The ID statement variable is also used for the labels and tool tips in the OBSERVATIONS plot.
In the VARIOGRAM procedure you can specify only one ID variable in the ID statement. If no ID statement is given, then PROC VARIOGRAM uses the observation number in the data sets and the OBSERVATIONS plot.