This is a simple text file; so basically it doesn't need any special highlighting. However it is useful to test the default.lang: this will be basically formatted in the output format, by replacing special chars of the output format. For instance, for html: we have &, < and >. This somehow shows how source-highlight can be used also as a simple formatter, without highlighting, e.g., to transform a text file into an HTML file or Tex file, and so on...