(Sun, from aviation) A user' s misconfiguration or misuse of a piece of software, producing apparently Bug-like results. E.g. "Joe Luser reported a Bug in sendmail that causes it to generate Bogus headers." "That' s not a Bug, that' s pilot error. His "sendmail.cf" is hosed." Compare UBD. [Jargon File] (1994-12-05)