This past weekend, Kim Kardashian West was criticized for appropriating black culture when she dressed up as Aaliyah for Halloween festivities, with many Twitter users arguing that Kim’s tribute to the late R&B artist was racially insensitive.

Before the Kardashians were targeted as repeat offenders, the cultural appropriation debate was playing out on college campuses—particularly around Halloween.

Two years after the 2015 debacle over culturally insensitive costumes at Yale, public and private universities across the country are doing their best to prevent students from wearing inappropriate or potentially offensive Halloween costumes.

The University of Michigan posted an October newsletter to its website reminding students that Halloween is a time when “many make inappropriate decisions about how to dress for the holiday and wear costumes that would constitute cultural appropriation.”

The U-Michigan newsletter offered examples—“Inuit costumes, Geisha costumes, gangster costumes, Native American costumes, etc.”—which could “reinforce offensive stereotypes and humiliate the people you are attempting to represent.”

Similarly, the University of Texas at Austin and the University of St. Thomas in Minnesota distributed fliers around campus illustrating the kinds of costumes that might be deemed offensive.

Awareness-raising efforts at other universities were made on a seemingly smaller scale. At Princeton University, for instance, the Center for Equality and Cultural Understanding hosted a seminar last week to “engage in a dialogue about the impact of cultural appropriation, Halloween, and why culture is not a costume.” (The university did not respond to Daily Beast requests for comment about the seminar.)

Likewise at Towson University in Maryland, the Center for Student Diversity reminded the school community that Halloween costumes “based on ethnic, racial, religious, gender, ability, and other cultural stereotypes are hurtful and reduce people’s identities into caricatures.”

Harvard University appeared to be an exception: in 2015 and 2016, students organized a “Happier Halloween for a Happier Harvard” campaign raising awareness around culturally insensitive costumes. Writing in The Harvard Independent, one student expressed concern that, without the campaign, campus would be crawling with white students in Native American headdresses and other offensive costumes.

Most college administrators know they can’t actually tell students what to wear and what not to wear, enforcing rules and threatening punishment, though Tufts University’s dean of students did just that last year, urging those in the school’s Greek community to file reports with campus police if they “encountered someone wearing an inappropriate and offensive costume.” Tufts did not respond to a Daily Beast request for comment regarding similar efforts this year.

Reached by The Daily Beast, several schools denied having official policies that police culturally or racially appropriating Halloween costumes.

Bowdoin College, which was mired by a cultural appropriation scandal last year, confirmed in an email to The Daily Beast that it was not taking any preventative measures ahead of Halloween.

Daniel Fitzgibbons, spokesperson for the University of Massachusetts-Amherst, allowed that the school’s resident assistants and peer advisers have cautioned students against wearing costumes that might offend fellow community members. “Generally we try and urge people to be respectful,” he said. “But there’s no overarching university policy.”