Which of the following is not required information in a donor's tax return?

In preparing a donor's tax return, certain pieces of information are mandatory while others may not be as essential. The information regarding the donor's past net gifts is not required because the donor's tax return focuses primarily on the gifts made during the current tax year and their associated details rather than a comprehensive history of all previous gifts.

On the other hand, the deductions claimed and allowable, the name of the donee, and the Tax Identification Number (TIN) of the donee are all vital pieces of information required to ensure accurate reporting and compliance with tax regulations. These elements help the taxing authority to verify the transaction and assess the tax implications of the gifts made. By focusing on the current year's gifts and pertinent details, the return can be accurately processed without the burden of historical data, which is why all previous net gifts made by the donor are not a requirement.