Used to create the decision tree. The variable key is used to define decision operations. Decision operations are marked in the table display with rule type D in column T (rule type).

In the operation field, you define the decision operation that you want to query. In the next line, you then enter the required specification for the decision operation in the VarKey column. (Variable key). In addition to the explicit specifications, you can also enter an asterisk (*) for all specifications that are unequal to the specifications already entered.