Privity of Contract: If it is not the person who signed the contract, it will not be prosecuted or prosecuted by others, and the signing of the contract has practical significance for both parties
Perivity of Contract: If it is not the person who signs the contract, it is not to be prosecuted or prosecuted, and the contract is of practical significance to both parties
Principle of contract: if you are not the person signing the contract, you will not be sued or sued by others. Moreover, signing the contract has practical significance for both parties