For example, Zhang San entrusts Li Si to attend the meeting. Zhang San is the principal and Li Si is the principal. The power of attorney should be signed by Zhang San.
Legal basis: Article 165 of the Civil Code of People's Republic of China (PRC) * * * If the power of attorney is in written form, the power of attorney shall specify the agent's name, agency matters, authority and time limit, and shall be signed or sealed by the client.