By making a reservation, you are agreeing to the terms of the pledge and will not patronize other steakhouses. This is only binding to the definition of patronize as "to be a frequent or regular customer of," e.g., "For some reason, he patronizes Del Frisco's regularly." If you are going by the alternate definition of patronize - "to adopt an air of condescension toward," - please feel free to engage in patronizing other steakhouses, e.g., "He patronizes Del Frisco's regularly about how cute their failed attempts to be Smith & Wollensky are."
In the event that you find yourself, whether through coercion, deceit or kidnapping, dining at a steakhouse other than Smith & Wollensky, you are required to act with the dignity inherent in a Smith & Wollensky customer, even when faced with inferior steaks, second-class service or a drink with an umbrella. However, your dignity does not preclude you from making snide comments and you should feel free to do so.
Entering a profane or obviously made-up last name will disqualify you from this offer, no matter how hilarious it may be.