BOSTON -- Welcome to Harvard. Feel free to pick a pronoun on this form: __ He. __ She. __ Ze. __ E. __ They.

During the registration process at Harvard University, students are now allowed to indicate which pronouns they use, with suggested gender-neutral options like "ze" or "they." Harvard isn't the first college to embrace gender-neutral pronouns, but it's among a wave of major institutions that are widening their policies and pronouns to acknowledge transgender students, as well as "genderqueer" students, who don't identify as male or female.

"If someone is being alienated or potentially outed by inappropriate gender references, we think that's not appropriate," said Michael Burke, registrar of Harvard's Faculty of Arts and Sciences.

American University posted a guide on its website explaining how to use pronouns like "ey," and how to ask someone which pronouns they use. Cornell University and MIT offer similar primers on their websites. Ohio University started letting students register their gender pronouns this year, and officials at Boston University said they're discussing the topic. Last week, the State University of New York, one of the nation's largest public college systems, announced that it's working on a data-collection tool to let students choose among seven gender identities, including "trans man," ''questioning" and "genderqueer."

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Advocates for transgender students applaud the changes, saying it can be insulting to be identified by the wrong pronoun.

"It feels really invalidating to have people make an assumption about what your gender is simply by looking at you," said Genny Beemyn, director of the Stonewall Center for lesbian, gay, bisexual and transgender students at the University of Massachusetts, Amherst.

Changes at places like Harvard, Beemyn said, represent "acceleration of a trend that we have been seeing for the past few years."

Beyond pronouns, more colleges are updating forms that in the past let students pick between male and female only. Applications to the University of California system include more options starting this year, letting students choose from labels including trans female or genderqueer. The move is meant to welcome those students, but for the first time it also lets the school track data on how transgender students fare on campus, such as their graduation rates.

"This is something that people think is long overdue," said Pamela Brown, the system's vice president of institutional research and academic planning.

Academics have suggested for years the idea that gender falls along a spectrum, not into two options. As early as 2009, schools like the University of Vermont were letting students pick their gender pronouns.

But the work of campus advocacy groups, plus the emergence of transgender figures in pop culture, has fueled wider change, experts say.

It's now commonplace for colleges to offer housing for transgender students. On the first day of class, some professors voluntarily ask students to provide their pronouns.

But on some campuses, change has provoked backlash.

The University of Tennessee, Knoxville, sparked outrage among state politicians in August when a post on the school website encouraged students to use pronouns such as "xe." State senators blasted the idea and called for an investigation of the post. Days later, by the order of the school president, it was taken down. A spokeswoman for the university declined to comment.

Grammarians, too, have chafed at the idea of pronouns that stretch modern English. Some individuals who don't identify as male or female use the pronoun "they," which some academics say should be reserved for plural subjects.

At Harvard, 4,000 students have submitted pronouns so far, with slightly more than 1 percent choosing something other than "he" or "she," said Burke, the registrar.

Laila Smith filled in "they" and "their" on the form, pronouns the junior started using earlier this year.

"By now, we've figured out that sexuality is fluid, gender is fluid," said Smith, who identifies as genderqueer. "I think that we're at the beginning of it all, and I hope to see this more integrated into the student life that I experience."

For now, there's nothing requiring students or professors to use the pronouns students pick. But Burke said the university is planning to train faculty members how to look up a student's pronouns, and explain their significance.

"We want this to be a place that is inclusive," Burke said, "and embracing of everybody in the community."