anchor.diff:        type = types.nullOr types.str;
         default = null;
         example = "eth1";
  -      description = ''
  -        Set rpcAddress OR rpcInterface, not both. Interfaces must
  +      description = mdDoc ''
  +        Set {option}`rpcAddress` OR {option}`rpcInterface`, not both. Interfaces must
           correspond to a single address, IP aliasing is not supported.
         '';
       };
  
positive.code:     user = mkOption {
        type = types.str;
        default = defaultUser;
        description = "Run Apache Cassandra under this user.";
      };
  
      group = mkOption {
        type = types.str;
        default = defaultUser;
        description = "Run Apache Cassandra under this group.";
      };
  
      homeDir = mkOption {
        type = types.path;
        default = "/var/lib/cassandra";
        description = ''
          Home directory for Apache Cassandra.
        '';
      };
  
negative.code:       type = types.nullOr types.str;
        default = "3w";
        example = null;
        description = mdDoc ''
          Set the interval how often full repairs are run, i.e.
          {command}`nodetool repair --full` is executed. See
          <https://cassandra.apache.org/doc/latest/operating/repair.html>
          for more information.
  
          Set to `null` to disable full repairs.
        '';
      };
  
  