anchor.diff:          example = "flat";
           description =
             ''
  -            Sets  the pointer acceleration profile to the given profile.
  -            Permitted values are adaptive, flat.
  +            Sets the pointer acceleration profile to the given profile.
  +            Permitted values are <literal>adaptive</literal>, <literal>flat</literal>.
               Not all devices support this option or all profiles.
               If a profile is unsupported, the default profile for this is used.
               <literal>flat</literal>: Pointer motion is accelerated by a constant
  
positive.code:         example = "/dev/input/event0";
          description =
            ''
              Path for ${deviceType} device.  Set to null to apply to any
              auto-detected ${deviceType}.
            '';
        };
  
negative.code:       transformationMatrix = mkOption {
          type = types.nullOr types.str;
          default = null;
          example = "0.5 0 0 0 0.8 0.1 0 0 1";
          description = ''
            A string of 9 space-separated floating point numbers. Sets the transformation matrix to
            the 3x3 matrix where the first row is (abc), the second row is (def) and the third row is (ghi).
          '';
        };
  