1907 and has become the second best-known society on campus. Some have suggested that Missouri's Mystical Seven was modeled after Virginia's Seven Society, which had been established just a couple of years earlier. Other secret societies followed, including Society of the Hidden Eye for junior, and senior men, LSV for senior women, Thadstek for freshman, and sophomore men, Tomb and Key for freshman, and sophomore men, and Kappa Kappa whose membership composition was unknown. During this period of rapid expansion of secret societies, a network of sub-rosa inter-fraternity organizations also established itself on campus with no purpose other than socializing and mischief-making. This network, known commonly as the "Greek Underworld" included organizations such as Seven Equals, Kappa Beta Phi, Sigma Phi Sigma, Kappa Nu Theta, and Sigma Alpha Beta. It is currently home to at least six secret honor societies that still participate in an annual public Taies Day ceremony at the end of each spring semester. QEBH, Mystical Seven, LSV, Alpha Xi chapter of Omicron Delta Kappa, Friars chapter of Mortar Board, and Rollins Society each use the Tap Day ceremony at the conclusion of the year to reveal the members who were initiated over the past year. Missouri is one of the few remaining institutions in which the local Omicron Delta Kappa and Mortar Board chapters carry out much of their work in secrecy. The Jefferson Society, which attempted to take part in Tap Day and was denied, claims to have been around since 1862. In addition to Tap Day activities, several of the societies maintain a public presence during some athletic events. QEBH is the caretaker of the Victory Bell, along with Nebraska's Society of Innocents, awarded to the winner of the Missouri–Nebraska Rivalry football game each year. The Friars Chapter of Mortar Board exchanges a gavel with Nebraska (The Black Masque Chapter of Mortar Board) at each MU-UNL football game, symbolizing the rivalry between the Universities. Mystical Seven and Oklahoma's Pe-et Society were likewise entrusted with the Peace Pipe trophy that was awarded to the winner of the biennial Missouri-Oklahoma football match. Omicron Delta Kappa previously served as the caretaker of the Indian War Drum trophy awarded to the winner of the annual Border War football game between Missouri and Kansas. University of North Carolina at Chapel Hill The library at the University of North Carolina at Chapel Hill contains the archives of the Order of