Question
What is a kill file?
Answer
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 the future. By extension, it may be used for a decision to ignore the person or subject in other media. 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.
— Source: Wikipedia (www.wikipedia.org)