There are many collegiate secret societies in North America. They vary greatly in their level of secrecy and the degree of independence from their universities. A collegiate secret society makes a significant effort to keep affairs, membership rolls, signs of recognition, initiation, or other aspects secret from the public. Some collegiate secret societies are referred to as "class societies", which restrict membership to one class year. Most class societies are restricted to the senior class and are therefore also called senior societies on many campuses. Categorization There is no strict rule on the categorization of secret societies. Secret societies can have ceremonial initiations, secret signs of recognition (gestures, handshakes, passwords), formal secrets, (the 'true' name of the society, a motto, or society history); but, college fraternities or "social fraternities" have the same, and some of these elements can also be a part of literary societies, singing groups, editorial boards, and honorary and pre-professional groups. Some secret societies have kept their membership secret, for example Seven Society and Gridiron, and some have not, like Skull and Bones (the Yale societies had published their membership lists in the yearbooks and the Yale Daily News). One key concept in distinguishing secret societies from fraternities is that, on campuses that have both kinds of organizations, one can be a member of both (that is, membership is not mutually exclusive). Usually, being a member of more than one fraternity is not considered appropriate, because that member would have divided loyalties; however, typically, there is no issue with being a member of a secret society and a fraternity, because they are not considered similar organizations or competing organizations. An especially difficult problem is the degree to which any one society is an actual society or is simply an honorary designation. Phi Beta Kappa, for example, was a true secret society, but after its secrets were divulged, the society continued. It claims today to still be an actual society that has meetings, conducts its affairs, and is a living social entity. For most members, membership consists of one evening's initiation, and no more, which would make the society completely an honorary one in most people's eyes. Many secret societies exist as honoraries on one campus and may have been actual meeting societies at one time, kept alive by one or two dedicated local alumni or an alumni affairs or Dean's office person, who see to it that