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 Lithuania.
Note that this tag cannot be used on all signatures, as not all signatures are copyright-free.
Article 5. Works not Attributed to the Subject Matter of Copyright
Copyright shall not apply to:
1) ideas, procedures, processes, systems, methods of operation, concepts, principles, discoveries or mere data;
2) legal acts, official documents texts of administrative, legal or regulative nature (decisions, rulings, regulations, norms, territorial planning and other official documents), as well as their official translations;
3) official State symbols and insignia (flags, coat-of-arms, anthems, banknote designs, and other State symbols and insignia) the protection of which is regulated by other legal acts;
4) officially registered drafts of legal acts;
5) regular information reports on events;
6) folklore works.
Hence it is assumed that this image has been released into the public domain. However, in some instances the use of this image might be regulated by other laws.
Uploaded a work by Arvydas Anušauskas from https://srsvb.lt/knygos-su-autografais-ir-linkejimais-siauliu-rajono-savivaldybes-viesosios-bibliotekos-fonduose/ with UploadWizard