anchor.diff:          type = types.bool;
           default = false;
           description = ''
  -          If yes, PDF will appear in export options. PDF will be created using
  +          If true, PDF will appear in export options. PDF will be created using
             pdflatex, which must be installed and in the path. Note that PDF
             exports create significant additional server load.
           '';
  
positive.code:         type = types.bool;
          default = true;
          description = ''
            If yes, all HTML (including that produced by pandoc) is filtered
            through xss-sanitize.  Set to no only if you trust all of your users.
          '';
        };
  
negative.code:       plugins = mkOption {
          type = types.path;
          description = ''
            Specifies a list of plugins to load. Plugins may be specified either
            by their path or by their module name. If the plugin name starts
            with Gitit.Plugin., gitit will assume that the plugin is an installed
            module and will not try to find a source file.
          '';
        };
  
  