Faced with rising furore over campus sex assaults, colleges across the US are spreading the word to students that it's wrong to have sex with anyone who for whatever reason - drugs, alcohol, exhaustion - has lost the mental capacity to consent.
Some schools also deliver another message: They prohibit sex outside of marriage.
This rule, found at Catholic University in the District of Columbia and certain others with religious affiliations, would seem at first glance to complicate efforts to prevent sexual assault. How can they tell unmarried students who want to have sex about the necessity of obtaining an effective yes when the rule book simply says no?
Schools that face this question say there is no dilemma.
A senior official at Catholic said the university, which has strong ties to the Vatican, upholds the church doctrine banning premarital sex but is "realistic and clear" with students about any potential sexual activity.
"Our teaching, of course, is that that relationship [should] be a product of exclusive love between two married people," said Lawrence Morris, the university's general counsel and a retired Army colonel.
"But any relationship anybody has has to be conducted in a respectful and appropriate manner. So we are just as clear to them, in a way that is consistent with the overall message of the university on that particular matter, about having consciousness of the other party's condition."
Pamphlets that Catholic distributes to students and policies listed online detail the university's guidance on incapacitation, consent and sexual misconduct, including a statement that consent "cannot be obtained from someone who is mentally or physically incapacitated whether due to drugs, alcohol or some other condition."
Catholic, with about 6,700 students, is one of dozens of colleges and universities under federal investigation for possible violation of antidiscrimination law in their handling of sexual violence reports. Catholic said it is cooperating fully and is confident that there will be "a just resolution of this matter".
The probe of Catholic arose from an incident in December 2012 in which a female student named Erin Cavalier said she was raped by a male student in her dormitory. The man - who was not charged with a crime - told investigators that Cavalier was a willing participant in a sexual encounter.
But Cavalier, who recently chose to give a public account of her case, told The Washington Post that she was so drunk that night, she blacked out and never gave consent.
An internal university inquiry, which Cavalier said was mishandled, cleared the man of her allegation that his actions violated the student conduct code.
Catholic University has declined to discuss the case.
One of its rules stipulates: "Sexual acts of any kind outside the confines of marriage are inconsistent with the teachings and moral values of the Catholic Church and are prohibited."
Asked how often the school enforces that rule, Catholic University spokesman Victor Nakas said that any possible violation is "most likely to come to our attention when it becomes a disruption to the residential community or negatively affects the living situation between roommates.
When it does, university staff address the behavior just as they would any other issue that is disruptive to the community or the roommate relationship."
Religious and moral questions inevitably pose challenges in the discussion of rules regarding sex on campus.
But Kevin Kruger, who is president of NASPA-Student Affairs Administrators in Higher Education, drew a parallel to alcohol policies. Underage drinking is illegal and banned on campuses, but that doesn't prevent university administrators from talking about responsible drinking, he said.
"You're acknowledging that something takes place and trying to help students make smart decisions," Kruger said. Some colleges, he said, will put condoms out in a student health center to reinforce the message that those who are sexually active should protect themselves.
Liberty University, an evangelical Christian school in Lynchburg, Virginia, prohibits its 13,000 residential students from drinking alcohol or having premarital sex on its campus. But Mark Hine, Liberty's senior vice president for student affairs, said the school covers sexual misconduct issues in sessions with students termed "keeping it safe".
"We do the education even though obviously our rule would prohibit sex outside of marriage," Hine said.
"Just because we prohibit it doesn't mean it's still not going to be considered by young adults with hormones raging."
Hine said the school impresses on male students that a woman could reach a point at which she is unable to consent to sexual activity. Hine and Liberty President Jerry Falwell Jr said they could not recall the last time the university disciplined a student for breaking the premarital sex ban.
Brigham Young University, closely connected with the Church of Jesus Christ of Latter-day Saints, prohibits sex outside of marriage for the 34,000 students on its campus in Provo, Utah.
BYU spokeswoman Carri Jenkins said the university takes numerous steps to teach students about sexual-assault prevention.
She pointed to a university initiative called "voices of courage" which aims to promote respect and nonviolence in relationships between men and women.
The initiative defines sexual abuse as "undesired sexual behaviour by one person upon another or taking advantage of someone not able to give consent
Jenkins said students who come to BYU know the university expects them to follow the Mormon law of chastity.
"It's how they have chosen to live their lives, and that's how it works," Jenkins said. "It's not that we have enforcement officers walking around. We couldn't possibly do that."
-The Washington Post