This article needs additional citations for verification. (September 2015) (Learn how and when to remove this template message)
A kill file (also killfile, bozo bin or twit list) is a file used by some Usenet reading programs to discard articles matching some unwanted patterns of subject, author, or other header lines. Adding a person or subject to one's kill file means that person or topic will be ignored by one's newsreader in the future. By extension, the term may be used for a decision to ignore the person or subject in other media.
Kill files were first implemented in Larry Wall's rn. Sometimes more than one kill file will be used. Some newsreader programs also allow the user to specify a time period to keep an author in the kill file.
Newer newsreader software like Gnus often provides a more advanced form of filter known as a score file, which can use multiple rules to determine which articles are shown. Web-based forums usually have a similar feature called an ignore list, which hides any posts by a specific user.
Jerry Pournelle wrote in 1986 of his wish for improvements to an offline reader for the Byte Information Exchange online service: "What I really need, though, is a program that will ... sort through the messages, assigning some to a priority file and others to the bit bucket depending on subject matter and origin".
- Pournelle, Jerry (March 1986). "All Sorts of Software". BYTE. p. 269. Retrieved 27 August 2015.