Signature block

For the cryptographic verifiable proof of authorship, see digital signature.
For post signing on Wikipedia, see Wikipedia:Signatures.
An email signature block example, using a female variant of the Alan Smithee pseudonym.

A signature block (often abbreviated as signature, sig block, sig file, .sig, dot sig, siggy, or just sig) is a personalized block of text automatically appended at the bottom of an email message, Usenet article, or forum post.