Source : Free On-Line Dictionary of Computing

hard-coded
     
         (By analogy with "{hard-wired}") Said of a data value
        or behaviour written directly into a program, possibly in
        multiple places, where it cannot be easily modified.  There
        are several alternatives, depending on how often the value is
        likely to change.  It may be replaced with a {compile-time}
        constant, such as a {C} "#define" {macro}, in which case a
        change will still require recompilation; or it may be read at
        {run time} from a {profile}, resource (see {de-rezz}), or
        {environment variable} that a {user} can easily modify; or it
        may be read as part of the program's input data.
     
        To change something hard-coded requires recompilation (if
        using a compiled language of course) but, more seriously, it
        requires sufficient understanding of the implementation to be
        sure that the change will not introduce inconsistency and
        cause the program to fail.
     
        For example, "The line terminator is hard-coded as newline;
        who in their right mind would use anything else?"
     
        See {magic number}.
     
        [{Jargon File}]
     
        (1999-10-18)