What is the definition of third party communications?

In amateur radio terminology, the "first party" is the transmitting control operator, and the "second party" is the receiving control operator. The "third party" is anyone else—an unlicensed person, an organization, or even another licensed amateur who is not directly operating the stations involved. Therefore, third-party communications involve sending a message or passing traffic on behalf of that outside person. This definition is strictly about who the message is for, rather than the equipment being used or how many radios are actively transmitting.