A short block of text at the end of a message identifying the sender and providing additional information about them.
A .sig file is small text file (with a .sig extension) that can be automatically attached to the end of email messages. The phrase SIG file is also used to identify blocks of text used for similar purposes through different channels, such as discussion group messages.
For personal use, SIG files often include humorous sayings or signature art. These can be automatically rotated so frequent recipients do not see the same message every time.
For business use, SIG files often include a mix of contact information and business promotion. This may include the sender’s name, job title, company name, phone #, fax #, email address, Web site address, tag line and brief benefits of your products or services.
There are netiquette issues concerning posting a sig in public forums. Some moderated forums discourage and disallow any form of self-promotional signature. As always, fully read the Terms & Conditions and get a feel for what is acceptable at a forum before posting.
Making Your SIG File Market for You
ClickZ (January 31, 2001)
E-Mail Signatures: One Size Does NOT Fit All
Looking After Your Signature File