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Signatures from WikiPedia:

A signature (from Latin signare, "to sign") is a handwritten (and sometimes stylized) depiction of someone's name, nickname or even a simple "X" that a person writes on documents as a proof of identity and intent. The writer of a signature is a signatory. Similar to a handwritten signature, a signature work describes the work as readily identifying its creator.

The traditional function of a signature is evidential: it is to give evidence of:

For example, the role of a signature in many consumer contracts is not solely to provide evidence of the identity of the contracting party, but rather to additionally provide evidence of deliberation and informed consent. This is why the signature often appears at the bottom or end of a document.

In many countries, signatures may be witnessed and recorded in the presence of a Notary Public to carry additional legal force.

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