A signature block (often abbreviated as signature, sig block, sig file, .sig, dot sig, siggy, or just sig) is a block of text automatically appended at the bottom of an e-mail message, Usenet article, or forum post. This has the effect of "signing off" the message and in a reply message of indicating that no more response follows. It is common practice for a signature block to consist of one or more lines containing some brief information on the author of the message. Note that a sig block is not the same as a digital signature. A sig block is easily forged, whereas a digital signature uses cryptographic techniques to provide verifiable proof of authorship.