All notices under this Plan must be in writing and will be deemed to have been given upon receipt of delivery by: (a) hand (against a receipt for such delivery), (b) certified or registered mail, postage prepaid, return receipt requested, or (c) a nationally recognized overnight courier service (against a receipt for such service). All notices to PHI related to this Plan should be sent to PHI’s principal business address. All notices to a Participant should be delivered to the most recent address as provided by such Participant to the human resources department of PHI.