The term signature refers to a signature file, or "sig" file, and is the on-line equivalent of a business card. A signature file is a short file typically containing information including the sender's contact addresses and number and, if desired, a salutation, which can be attached to outgoing e-mail messages. Additionally, the term signature is also increasingly being used to designate the addition of a digitized hand-written signature to documents.

The purpose of a signature file is to identify the user. The sender's name, company name if appropriate, the sender's position in the company, phone and fax numbers, mailing address, and a Web site URL (Uniform Resource Locator) are typically part of a signature. A business or personal salutation can be included as well. Another common inclusion is known as ASCII art--a drawing made using the symbols on a standard keyboard. ASCII characters are the medium of choice...