Hòa Hảo, historian Hue-Tam Tai argues that Sổ's frightening predictions had a role in the increased frequency of such incidents in the 1940s. Historically, Vietnamese sectarian preachers were expected to perform magical and healing acts, but Hòa Hảo writers believed that magic was superstition, and hence incompatible with Zen's non-exertion spirit. Traditionally, a missionary had to demonstrate his special abilities before his preaching could be accepted, which necessitated the use of magic. Tai believes that the emphasis stems from the illiteracy of the Mekong Delta's population. She contrasts this with Chinese sects, which used the written word more frequently, but their adherents were also more settled within their communities. The lack of religious literature and the concentration on magical proof encouraged a style of leadership based on personal charisma rather than inherited legitimacy. Its adherents have their own flag, a brown rectangle with no characters or pictures. The Hòa Hảo insignia is circular and brown, with a white lotus in the center and the initials P.G.H.H. () on top. They also have their own special holidays; the Hoahaoists celebrate three festival days each Vietnamese lunisolar year: 18th day of the 5th month, the anniversary of the founding of Hòa Hảo Buddhism; 25th day of the 11th month, the founder's nativity; and 25th day of the 2nd month, the date of the founder's "disappearance". To become a follower, a candidate must introduce oneself to the village management committee with the assistance of two confirmed devotees who are familiar with the religious precepts and moral restrictions. The convert returns home after being publicly accepted to tell their family that they have taken shelter alongside the Three Jewels of Buddhism and are praying before the ancestors' altar, and then a copy of Sổ's work is given to the convert. If no management committee exists, the convert is led by two adherents until they can visit the nearest committee. Anyone who wishes to leave the community must inform two followers or the committee of their decision. Anyone who goes against Sổ's teachings is expelled from the community, and they are solely responsible for their actions. The village management boards fell under the jurisdiction of an interprovincial board and, ultimately, a central management board, which was in charge of Buddhist education and the application of the conditions of admittance into the faith, beginning in the late 1940s. However, because it was controlled by military factions,