severe problem. For example, the delivery country can be checked against the street address or postal codes and any mismatch can generate an error panel displayed to the user, who will then presumably make the correction. In cases where there is no clear majority and the results cannot easily be verified by other available information, such as the gender of the individual, no default should be offered. Some software applications, however, require that default values be supplied. A 1982 Apple Computer manual for developers warned: "Please do not ever use the word default in a program designed for humans. Default is something the mortgage went into right before the evil banker stole the Widow Parson's house. There is an exhaustive list of substitutes (previous, automatic, standard, etc.)". In computer languages Many languages in the C family (but not C itself, as of C11) allow a function to have default parameters or default arguments, that are used if the function is called with omitted parameter specifications. In C and programming languages based on its syntax, the switch statement (which dispatches among a number of alternatives) can make use of the default keyword to provide a case for when no other case matches. In Fortran, the INIT parameter on a declaration defines an initial default value for that variable. In Rust, types that implement the Default trait can produce a default value. For example, the primitive integer types in Rust implement the Default trait by returning 0. In operating systems In operating systems using a command line interface, the user types short commands often followed by various parameters and options. See also Principle of least astonishment Convention over configuration References Computing terminology Computer data