16 CFR § 316.4 - Requirement to place warning labels on commercial electronic mail that contains sexually oriented material.
(a) Any person who initiates, to a protected computer, the transmission of a commercial electronic mail message that includes sexually oriented material must:
(1) Exclude sexually oriented materials from the subject heading for the electronic mail message and include in the subject heading the phrase “SEXUALLY-EXPLICIT: ” in capital letters as the first nineteen (19) characters at the beginning of the subject line; 2
2 The phrase “SEXUALLY-EXPLICIT” comprises 17 characters, including the dash between the two words. The colon (:) and the space following the phrase are the 18 th and 19 th characters.
(2) Provide that the content of the message that is initially viewable by the recipient, when the message is opened by any recipient and absent any further actions by the recipient, include only the following information:
(i) The phrase “SEXUALLY-EXPLICIT: ” in a clear and conspicuous manner; 3
3 This phrase consists of nineteen (19) characters and is identical to the phrase required in 316.5(a)(1) of this Rule.
(ii) Clear and conspicuous identification that the message is an advertisement or solicitation;
(iii) Clear and conspicuous notice of the opportunity of a recipient to decline to receive further commercial electronic mail messages from the sender;
(iv) A functioning return electronic mail address or other Internet-based mechanism, clearly and conspicuously displayed, that
(A) A recipient may use to submit, in a manner specified in the message, a reply electronic mail message or other form of Internet-based communication requesting not to receive future commercial electronic mail messages from that sender at the electronic mail address where the message was received; and
(B) Remains capable of receiving such messages or communications for no less than 30 days after the transmission of the original message;
(v) Clear and conspicuous display of a valid physical postal address of the sender; and
(vi) Any needed instructions on how to access, or activate a mechanism to access, the sexually oriented material, preceded by a clear and conspicuous statement that to avoid viewing the sexually oriented material, a recipient should delete the email message without following such instructions.
(b) Prior affirmative consent. Paragraph (a) does not apply to the transmission of an electronic mail message if the recipient has given prior affirmative consent to receipt of the message.