17 CFR § 240.14a-10
Prohibition of certain solicitations
April 15, 2021
No person making a solicitation which is subject to §§240.14a-1 to 240.14a-10 shall solicit:
(a) Any undated or postdated proxy; or
(b) Any proxy which provides that it shall be deemed to be dated as of any date subsequent to the date on which it is signed by the security holder.
[17 FR 11434, Dec. 18, 1952]