The directory separator is platform specific. On Windows, the indicator is double back slash (\\) when specifying the paths for a recipe file location or a command line argument location. You can also use the syntax ${dir.sep} as a directory separator. When ${dir.sep} is used in wpc_preferences.txt file, the $ is replaced by \\. The \\ and the ${dir.sep} separators can be used in combination, as in the following example: