The clip comes from the everyday bell system at Vlietland College, a Dutch secondary school, where it marked lesson changes for students moving between classrooms. Shared online under the short name VLC, it spread as a recognisable school sound that former pupils instantly knew and others adopted for classroom jokes. Unlike a boxing bell used for rounds, this tone is longer and more electronic, built to be heard down corridors. It remains popular because almost everyone associates that urgent ringing with school routines, deadlines and the relief of a break.