# Meta Attributes

Like Nix packages, NixOS modules can declare meta-attributes to provide extra information. Module meta attributes are defined in the `meta.nix` special module.

`meta` is a top level attribute like `options` and `config`. Available meta-attributes are `maintainers` and `doc`.

Each of the meta-attributes must be defined at most once per module file.

    { config, lib, pkgs, ... }:
    {
      options = {
        ...
      };

      config = {
        ...
      };

      meta = {
        maintainers = with lib.maintainers; [ ericsagnes ];
        doc = ./default.xml;
      };
    }

`maintainers` contains a list of the module maintainers.

`doc` points to a valid DocBook file containing the module documentation. Its contents is automatically added to . Changes to a module documentation have to be checked to not break building the NixOS manual:

    $ nix-build nixos/release.nix -A manual