TELLTALE is written in ANSI "C" and, as a convenient programming short-cut, uses the the "C" library text facilities in order to do some of the processing of the users' command-line options. This means that the user has to conform to some of the library's requirements. The major requirement is that all "escape" sequences must be in lower-case. So for example, while "%d" and "\n" are acceptable, "%D" and "\N" are not.