Signature Block - E-mail and Usenet

E-mail and Usenet

An e-mail signature is a block of text appended to the end of an e-mail message often containing the sender's name, address, phone number, disclaimer or other contact information. Most e-mail clients, including Mozilla Thunderbird and Eudora, can be configured to automatically append an e-mail signature with each new message. A shortened form of a signature block (sometimes called a "signature line"), only including one's name, often with some distinguishing prefix, can be used to simply indicate the end of a post or response. Most e-mail servers can be configured to append e-mail signatures to all outgoing mail as well. However, when multiple replies to the same post occur, care should be taken to prevent multiple signatures from building up so that message lengths remains legible and message size manageable.

Since by definition these blocks are added automatically to a message, usually regardless of its content, there are guidelines of netiquette regarding their size. The most common guideline, called the McQuary limit, is a size of no more than four lines of less than eighty columns each. This keeps the overall size of the message down, conserving bandwidth as well as the time required to read the message, and ensures that eighty-column terminals can display the sig block properly.

The formatting of the sig block is prescribed somewhat more firmly: it should be displayed as plain text in a fixed-width font (no HTML, images, or other rich text), and must be delimited from the body of the message by a single line consisting of exactly two hyphens, followed by a space, followed by the end of line (i.e., "-- \n"). This latter prescription, which goes by many names, including "sig dashes", "signature cut line", "sig-marker", "sig separator" and "signature delimiter", allows software to automatically mark or remove the sig block as the receiver desires. The signature prefix chosen can be different for different people serving as a distinguishing feature of their signatures. A correct delimiter is required for a news posting program to receive the Good Netkeeping Seal of Approval.