A signature (/ˈsɪɡnətʃər/; from Latin:signare, "to sign") is a handwritten (and often stylized) depiction of someone's name, nickname, or even a simple "X" or other mark that a person writes on documents as a proof of identity and intent. The writer of a signature is a signatory or signer. Similar to a handwritten signature, a signature work describes the work as readily identifying its creator. A signature may be confused with an autograph, which is chiefly an artistic signature. This can lead to confusion when people have both an autograph and signature and as such some people in the public eye keep their signatures private whilst fully publishing their autograph.
Function and types
The traditional function of a signature is evidential: it is to give evidence of:
The provenance of the document (identity)
The intention (will) of an individual with regard to that document
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 also to provide evidence of deliberation and informed consent.
A signature is a hand-written, possibly stylized, version of someone's name, which may be used to confirm the person's identity. The writer of a signature is a signatory or signer.
Signature or signatory may also refer to:
distinctive, characteristic indicative of identity
Signature artwork, works by popular and well-established artists that are easily recognized as theirs because of unique characteristics in style, medium, or subject matter; distinctive works that may be easily recognized without having to ascertain the makers, the school of art, or the period
Signature block, text automatically appended at the bottom of an e-mail message, Usenet article, or forum post
Method signature, in computer programming, especially object-oriented programming, how a method is commonly identified
Type signature, which defines the inputs and outputs for a function or method
Blind signature, digital signature in which the content of a message is disguised
which can be identified with Z. Therefore cup product, under these hypotheses, does give rise to a symmetric bilinear form on H2k(M,Z); and therefore to a quadratic form Q. The form Q is non-degenerate due to Poincaré duality, as it pairs non-degenerately with itself. More generally, the signature can be defined in this way for any general compact polyhedron with 4n-dimensional Poincaré duality.