To provide a collaboration system and its chat system wherein a chat can be conducted by designating clearly and simply a position of an object to be noticed in a working image. Specifically, this process comprises adding a peroxyacid to a natural oil wherein said natural oil and said peroxyacid react to form an epoxidized natural oil and adding said epoxidized natural oil to a mixture of an alcohol, water, and a fluoboric acid catalyst. The power receiving device includes a piezoelectric resonator, a load, a power receiving device side passive electrode, and a power receiving device side active electrode. The unique identifiers exchanged during auto-negotiation can be passed up to higher layers for an integrity check of unique identifiers exchanged using higher layer protocols.