If the filing threshold has been met, or in other words, if, independent of the portability election, the estate is required to file an estate tax return based on the total value of the gross estate and adjusted taxable gifts, no extension of time to elect portability is available and Revenue Procedure 2017-34 does not apply.
Verification is the process of assuring that the product satisfies the conditions before work starts. Validation is the process of assuring that the product meets the specified requirements at the end of the development phase. In other words, to make sure the product is designed in accordance with customer's requirements.
Data validation is intended to provide certain well-defined guarantees for fitness, accuracy, and consistency for any of various kinds of user input into an application or automated system. Data validation rules can be defined and designed using any of various methodologies, and be deployed in any of various contexts.