(a) Claims deemed received. A claim will be deemed to have been received by the Commission on the date postmarked, if mailed, or if delivery is made in person, on the date of delivery at the offices of the Commission in Washington, DC.

(b) Claims developed. In the event that a claim has been insufficiently prepared so as to preclude processing thereof, the Commission may request the claimant to furnish whatever supplemental evidence, including the completion and execution of an official claim form, as may be essential to the processing of the claim. In case the evidence or official claim form requested is not returned within the time which may be designated by the Commission, the claim may be deemed to have been abandoned and may be disallowed.