A controversy has erupted after an apology letter written by a Yonsei University College of Dentistry student for violating dress code regulations was publicly posted in a classroom.

According to reports, the apology letter written by a student at the Yonsei University College of Dentistry stated, "I violated the dress code by coming to school wearing shorts due to the careless thought that the weather was hot," adding, "It was a disqualifying factor as a prospective medical professional and showed a lax attitude."

The student also wrote, "I deeply reflect on violating the dress code due to my carelessness."

Currently, a notice titled "Appropriate Student Attire for Dental School Life" is posted on the undergraduate website of the Yonsei University College of Dentistry.

The notice recommends "dressing like a dental student," outlining dress guidelines that prohibit shorts, short skirts, and slippers, while requiring socks that rise above the ankles.

It also includes instructions such as "do not wear shoes with the backs stepped on."

As the incident became known, criticisms poured in on the university's online student community, with comments such as, "Even granting that slippers might pose a safety issue, publicly displaying the apology letter in the classroom to the entire school is close to anachronistic collective bullying."

In response, the Yonsei University College of Dentistry explained that the measure was an educational step taken to guide students on the attitude required as prospective medical professionals, adding that it could discuss potential improvements to the dress code for non-clinical settings with students moving forward.

Reported by Lee Hyeon-yeong | Video by Seo Byeong-wook | Design by Lee Su-min | Produced by SBS Digital News