Tips for Creating Terms - Regression
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1    When Minitab creates an interaction, the order of the predictors in the interaction is the same as the order of the predictors in the list of predictors. If you do not like this order, you can go back to the main dialog an change the order there. However, continuous predictors are always before categorical predictors.

2    If you create a term with duplicate categorical predictors, Minitab removes the extra categorical predictors. For example, suppose A, B, and C are categorical predictors, and you cross A*B with B*C. This gives A*B*B*C.  You cannot have two B’s so Minitab removes the extra one and adds A*B*C to the model.