Do not modify the factory.prp file to make individual site requirements. Instead, change the site.prp file for an individual site. Settings in the site.prp file override the settings in the factory.prp file. In this way, you can always return to factory default settings when needed. In addition, do not modify the language-specific factory<lang>.prp files either. To add a new environment as a possible selection for a configuration, see Modifying the site<lang>.prp files