kill file

n. [Usenet; very common] (alt.: KILL file ) Per-user file(s) used by some
Usenet reading programs (originally Larry Wall's rn (1) ) to discard
summarily (without presenting for reading) articles matching some
particularly uninteresting (or unwanted) patterns of subject, author, or
other header lines. Thus to add a person (or subject) to one's kill file is
to arrange for that person to be ignored by one's newsreader in future. By
extension, it may be used for a decision to ignore the person or subject in
other media. See also plonk.

