nasal demons

n. Recognized shorthand on the Usenet group comp.std.c for any unexpected
behavior of a C compiler on encountering an undefined construct. During a
discussion on that group in early 1992, a regular remarked When the compiler
encounters [a given undefined construct] it is legal for it to make demons
fly out of your nose (the implication is that the compiler may choose any
arbitrarily bizarre way to interpret the code without violating the ANSI C
standard). Someone else followed up with a reference to nasal demons , which
quickly became established. The original post is web-accessible at
http://groups.google.com/groups?hl=en selm=10195%40ksr.com.