The membership certificate of the Tsung Peh Society, a Hakka secret society in Singapore that originated from the Tiandihui (Heaven and Earth Society), can be distinguished by esoteric forms in the four triangles in the top and bottom left corners. The meaning of these is not known. Such membership certificates were carried around by members of the secret societies for identification purposes. The various secret societies also devised special syntaxes to obscure the meaning of the text on the certificates to prevent outsiders from deciphering its overall meaning. The local version of the Tiandihui originated from the secret society in China, a sworn fraternity comprising Chinese men with the common aim of overthrowing the Qing dynasty and restoring the Ming. With increased Chinese migration to Singapore, the local society became a form of mutual-aid and support, and various splinter groups (hui or kongsi) subsequently emerged among the main dialect groups.