Pornographic "spam" e-mail will have to be clearly labeled by mid-June to allow Internet users to easily filter it out, the Federal Trade Commission announced Wednesday.
Unsolicited pornography will have to bear a label reading "SEXUALLY-EXPLICIT-CONTENT:" in the subject line and the messages themselves will not be allowed to contain graphic material, the FTC said.
Outrage over unsolicited pornography and other forms of unsolicited e-mail spurred Congress to pass the first nationwide anti-spam law last year, which required the FTC to develop labels for smut.
An FTC study released last spring found that 17 percent of pornographic offers contained images of nudity that appeared whether a recipient wanted to see them or not.
The new rule is intended to change that. Pornographers will not be allowed to include sexually explicit pictures in the body of the message, though they will be allowed to include hyperlinks or other methods to access their material.
Like other e-mail marketers, they will also be required to include their postal address and an easy way to opt out of future mailings.
Several states have already passed laws requiring pornographic spam to bear an "ADV:ADULT" label or some variant, but they will be overridden by the federal standard.
The FTC determined the "adult" tag was too vague as it could apply to gambling or tobacco, an official said.
"Lots of things are appropriate for adults that aren't appropriate for children," said FTC Assistant Director Allen Hile.
The hyphenated "SEXUALLY-EXPLICIT-CONTENT:" label, while ungrammatical, will make it easier to block explicit content while letting through messages from anti-pornography groups or others who may use the phrase, the FTC said in its notice.
The public will have three weeks to comment on the proposal, which is due to take effect in mid-June.
Hile said the agency is especially interested to hear whether the measure will encounter any technical hurdles. Free-speech arguments will carry less weight as the agency has been directed by Congress to develop the labels, he said.
"We don't have a whole lot of discretion in this," Hile said. "I guess we can't prevent commenters from saying, 'What a stupid idea,' or 'It violates the Constitution' or whatever, but we can't do anything with that."