module ietf-yang-metadata {

  namespace "urn:ietf:params:xml:ns:yang:ietf-yang-metadata";

  prefix md;

  organization

    "IETF NETMOD (NETCONF Data Modeling Language) Working Group";

  contact

    "WG Web:   <https://datatracker.ietf.org/wg/netmod/>

     WG List:  <mailto:netmod@ietf.org>

     WG Chair: Lou Berger

               <mailto:lberger@labn.net>

     WG Chair: Kent Watsen

               <mailto:kwatsen@juniper.net>

     Editor:   Ladislav Lhotka

               <mailto:lhotka@nic.cz>";

  description

    "This YANG module defines an 'extension' statement that allows

     for defining metadata annotations.

     Copyright (c) 2016 IETF Trust and the persons identified as

     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or

     without modification, is permitted pursuant to, and subject to

     the license terms contained in, the Simplified BSD License set

     forth in Section 4.c of the IETF Trust's Legal Provisions

     Relating to IETF Documents

     (http://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC 7952

     (http://www.rfc-editor.org/info/rfc7952); see the RFC itself

     for full legal notices.";

  revision 2016-08-05 {

    description

      "Initial revision.";

    reference

      "RFC 7952: Defining and Using Metadata with YANG";

  }

  extension annotation {

    argument name;

    description

      "This extension allows for defining metadata annotations in

       YANG modules.  The 'md:annotation' statement can appear only

       at the top level of a YANG module or submodule, i.e., it

       becomes a new alternative in the ABNF production rule for

       'body-stmts' (Section 14 in RFC 7950).

       The argument of the 'md:annotation' statement defines the name

       of the annotation.  Syntactically, it is a YANG identifier as

       defined in Section 6.2 of RFC 7950.

       An annotation defined with this 'extension' statement inherits

       the namespace and other context from the YANG module in which

       it is defined.

       The data type of the annotation value is specified in the same

       way as for a leaf data node using the 'type' statement.

       The semantics of the annotation and other documentation can be

       specified using the following standard YANG substatements (all

       are optional): 'description', 'if-feature', 'reference',

       'status', and 'units'.

       A server announces support for a particular annotation by

       including the module in which the annotation is defined among

       the advertised YANG modules, e.g., in a NETCONF <hello>

       message or in the YANG library (RFC 7950).  The annotation can

       then be attached to any instance of a data node defined in any

       YANG module that is advertised by the server.

       XML encoding and JSON encoding of annotations are defined in

       RFC 7952.";

  }

}