Potential breaches may be observed during play directly by a tournament arbiter. They can also
be reported to the arbiter by a player, a spectator or, indeed, the FPL (e.g., based on statistical
analysis or on-site inspection).
Potential cheating may also be reported after a tournament has been completed, based, for example, on new findings (e.g., signs of improper use of devices, confessions, statistical evidence). In general, a Post Tournament Complaint (PTC) should be based on very substantial evidence, and complainants are required to illustrate their case in great detail for the FPL to consider it. PTCs can be filed only by interested parties such as players, Federations, and chess officials.