This is an example addendum to the conference anti-harassment policy for conferences in which topics prohibited by the main policy are on topic. See this discussion before adopting.
Exception: Discussion or images related to sex, pornography, discriminatory language, or similar is welcome if it meets all of the following criteria: (a) the organizers have specifically granted permission in writing, (b) it is necessary to the topic of discussion and no alternative exists, (c) it is presented in a respectful manner, especially towards women and LGBTQIA people, (d) attendees are warned in advance in the program and respectfully given ample warning and opportunity to leave beforehand. This exception specifically does not allow use of gratuitous sexual images as attention-getting devices or unnecessary examples.
[If some topics are going to be the subject of general discussion, add a blanket approval for those topics from the conference organizers here, which counts as "the organizers have specifically granted permission in writing" and is subject to the rest of the requirements.]