You have the option of waiving those rules (defined for the product), which you do not wish to apply on a contract.

For example, for a product, there can be one interest rule for the main interest (for example, 14%). You can have a tenor-based commission defined as an interest rule for the same product (for example, 3%). Both these will apply to contracts involving the product. However, you can waive these rules for a specific contract. For instance, you can waive the 3% commission on the contract (by checking the Waive field).