>>Read more trending stories

One group of girls had a simple message for yearbook readers: "We are not related."

The girls - Alice, Kim, Theresa and Vivian - all share the last name Nguyen (pronounced "win").

In 2012, eight girls graduating from Presentation High School in San Jose, California had a similar message.

According to one Reddit user, the last name Nguyen is popular because when the Nguyen Dynasty seized power in Vietnam in the early 19th century, its leaders "awarded" the last name to many citizens. 

"Many Vietnamese changed their name or were rewarded the honored name Nguyen during the Nguyen dynasty's rule, so a man who had his name changed would marry a woman, whose name would now be Nguyen, who'd have many children, all of them all being Nguyen as well," the user wrote.