16 CFR 456.3: Verifiable affirmative consent to providing the prescription in a digital format.

For a prescription copy provided in a digital format, the prescriber shall:

(a) Identify to the patient the specific method or methods of electronic delivery that will be used, such as text message, electronic mail, or an online patient portal;

(b) Obtain, on paper or in a digital format, the patient's verifiable affirmative consent to receive a digital copy through the identified method or methods; and

(c) Maintain records or evidence of a patient's affirmative consent for a period of not less than three years. Such records or evidence shall be available for inspection by the Federal Trade Commission, its employees, and its representatives.