This signature is believed to be ineligible for copyright and therefore in the public domain because it falls below the required level of originality for copyright protection both in the United States and in the source country (if different). In this case, the source country (e.g. the country of nationality of the signatory) is believed to be Kina.

This image is now in the public domain in China because its term of copyright has expired.

According to copyright laws of the People's Republic of China (with legal jurisdiction in the mainland only, excluding Hong Kong and Macao), amended November 11, 2020, Works of legal persons or organizations without legal personality, or service works, or audiovisual works, enter the public domain 50 years after they were first published, or if unpublished 50 years from creation. For photography works of natural persons whose copyright protection period expires before June 1, 2021 belong to the public domain. All other works of natural persons enter the public domain 50 years after the death of the creator.
According to copyright laws of Republic of China (currently with jurisdiction in Taiwan, Penghu, Kinmen, Matsu, etc.), all photographs and cinematographic works, and all works whose copyright holder is a juristic person, enter the public domain 50 years after they were first published, or if unpublished 50 years from creation, and all other applicable works enter the public domain 50 years after the death of the creator.

Important note: Works of foreign (non-U.S.) origin must be out of copyright or freely licensed in both their home country and the United States in order to be accepted on Commons. Works of Chinese origin that have entered the public domain in the U.S. due to certain circumstances (such as publication in noncompliance with U.S. copyright formalities) may have had their U.S. copyright restored under the Uruguay Round Agreements Act (URAA) if the work was under copyright in its country of origin on the date that the URAA took effect in that country. (For the People's Republic of China, the URAA took effect on January 1, 1996. For the Republic of China (ROC), the URAA took effect on January 1, 2002.[1])