Google yourself. Curate your online photos. The general rule of thumb, as one private high school advises its students: Don’t post anything you wouldn’t want your grandmother to see.

Guidance counselors have warned college applicants for years to mind their social media posts but can now cite a high-profile example at Harvard University, which revoked offers of admission to 10 students for offensive Facebook posts.

Colleges rarely revoke admission for online offenses, but social media’s role in the college admission process is a growing reality. Here are some experts’ tips on what to post – and not post – if you’re trying to get into college.

WHAT RESEARCH SHOWS

Research from Kaplan Test Prep suggests online scrutiny of college applicants is increasing. Of 365 admissions officers surveyed, 35 percent said they check Instagram, Facebook, Twitter and other social media sites to learn more about applicants, according to a poll released in February.

The Harvard case highlights that “admissions doesn’t necessarily end at the acceptance letter,” says Yariv Alpher, executive director of research for Kaplan. The case included jokes about the Holocaust and sexual assault that were shared on a private Facebook group for incoming Harvard freshmen, according to The Harvard Crimson.

GRANDMOTHER RULE

San Francisco University High School seniors are given a warning each fall to clean up their online presence – and nix any posts they wouldn’t show Grandma, said Jon Reider, director of college counseling at the elite private school.

Another word of wisdom: Don’t make jokes online.

“Unless you are certified as being the funniest kid in the class, don’t be funny,” Reider said. “A sense of humor can be dangerous online.”

WRONGDOING ONLINE

Colgate University admissions officers don’t routinely cruise prospective students’ social media sites, says dean of admissions Gary L. Ross.

But he cited a case from a few years ago where a student bragged on social media that she applied early to Colgate and another institution, which violates an agreement students sign to apply early to only one school.

EDIT USER NAMES

Make sure your email address is appropriate, says Nancy Beane, associate director of college counseling at The Westminster Schools in Atlanta, and president of the National Association for College Admission Counseling.

Silly, vulgar or otherwise unprofessional usernames might look good to teenagers but send the wrong message to adults.

MORE DOS AND DON’TS

The Princeton Review offers social media tips for college applicants, including “Google yourself” to see what turns up.

“Maybe you’ve made a comment on a blog that you’d rather not have show up, or a friend has tagged you in an unflattering photo,” Princeton Review says in a tip sheet on its website.