<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE rfc SYSTEM "rfc2629.dtd" []>
<?xml-stylesheet type="text/xsl" href="rfc2629.xslt"?>
<?rfc toc="yes"?>
<?rfc compact="no"?>
<?rfc subcompact="no"?>
<?rfc symrefs="yes" ?>
<?rfc sortrefs="yes"?>
<?rfc iprnotified="no"?>
<?rfc strict="yes"?> "rfc2629-xhtml.ent">

<rfc xmlns:xi="http://www.w3.org/2001/XInclude" ipr="trust200902"
     submissionType="IETF" category="std" consensus="true"
     number="8819" docName="draft-ietf-netmod-module-tags-10" updates="8407"
     submissionType="IETF">
     obsoletes="" xml:lang="en" tocInclude="true" symRefs="true"
     sortRefs="true" version="3">

  <!-- xml2rfc v2v3 conversion 2.41.0 -->
  <front>
    <title abbrev="YANG Module Tags">YANG Module Tags</title>
    <seriesInfo name="RFC" value="8819" />
    <author initials='C.' surname='Hopps' fullname='Christian Hopps'><organization>LabN initials="C." surname="Hopps" fullname="Christian Hopps">
      <organization>LabN Consulting, L.L.C.</organization><address><email>chopps@chopps.org</email></address></author>
<author initials='L.' surname='Berger' fullname='Lou Berger'><organization>LabN L.L.C.</organization>
      <address>
        <email>chopps@chopps.org</email>
      </address>
    </author>
    <author initials="L." surname="Berger" fullname="Lou Berger">
      <organization>LabN Consulting, LLC.</organization><address><email>lberger@labn.net</email></address></author>
<author initials='D.' surname='Bogdanovic' fullname='Dean Bogdanovic'><organization>Volta Networks</organization><address><email>ivandean@gmail.com</email></address></author>  <date/><abstract><t>This LLC.</organization>
      <address>
        <email>lberger@labn.net</email>
      </address>
    </author>
    <author initials="D." surname="Bogdanovic" fullname="Dean Bogdanovic">
      <organization>Volta Networks</organization>
      <address>
        <email>ivandean@gmail.com</email>
      </address>
    </author>
    <date month="September" year="2020" />

<keyword>YANG</keyword>
<keyword>tags</keyword>

    <abstract>
      <t>This document provides for the association of tags with YANG
      modules. The expectation is for such tags to be used to help classify
      and organize modules. A method for defining, reading reading, and writing a
      modules tags is provided. Tags may be registered and assigned during
      module definition; definition, assigned by implementations; implementations, or dynamically defined
      and set by users. This document also provides guidance to future model
      writers; as such, this document updates RFC8407.</t></abstract> RFC 8407.</t>
    </abstract>
  </front>
  <middle>
    <section title="Introduction"> numbered="true" toc="default">
      <name>Introduction</name>
      <t>The use of tags for classification and organization is fairly
      ubiquitous not only within IETF protocols, protocols but in the internet itself
      (e.g., <tt>#hashtags</tt>).
<!--[rfced] When we converted this document to v3, xml2rfc converted <spanx style='verb'>#hashtags</spanx>).
style="verb"> to <tt>. In the html and pdf output, the text enclosed in <tt>
is output in fixed-width font. In the txt output, the text enclosed in <tt>
appears in quotation marks.

Please review carefully and let us know if the output is acceptable or if any
updates are needed.
-->
      One benefit of using tags for organization
      over a rigid structure is that it is more flexible and can more easily
      adapt over time as technologies evolve. Tags can be usefully registered,
      but they can also serve as a non-registered mechanism available for
      users to define themselves. This document provides a mechanism to define
      tags and associate them with YANG modules in a flexible manner. In
      particular, tags may be registered as well as assigned during module definition;
      definition, assigned by implementations; implementations, or dynamically defined and set
      by users.</t>
      <t>This document defines a YANG module <xref target="RFC7950"/> which target="RFC7950"
      format="default"/> that provides a list of module entries to allow for
      adding or removing of tags as well as viewing the set of tags associated
      with a module.</t>
      <t>This document defines an extension statement to be used to indicate
      tags that SHOULD <bcp14>SHOULD</bcp14> be added by the module implementation
      automatically (i.e., outside of configuration).</t>
      <t>This document also defines an IANA registry for tag prefixes as well
      as a set of globally assigned tags.</t>
      <t><xref target="sec-guidelines-to-model-writers"></xref> target="sec-guidelines-to-model-writers" format="default"/>
      provides guidelines for authors of YANG data models.</t>
      <t>This document updates <xref target="RFC8407"/>.</t> target="RFC8407" format="default"/>.</t>
      <t>The YANG data model in this document conforms to the Network
      Management Datastore Architecture (NMDA) defined in <xref target="RFC8342"/>.</t> target="RFC8342"
      format="default"/>.</t>
      <section title="Some possible use cases numbered="true" toc="default">
        <name>Some Possible Use Cases for YANG module tags"> Module Tags</name>
        <t>During this documents's development document's development, there were requests for example
	uses of module tags. The following are a few example use cases for
	tags. This list is certainly not exhaustive.</t>
        <t>One example use of tags would be to help filter different discrete
	categories of YANG modules supported by a device. For example, if
	modules are suitably tagged, then an XPath query can be used to list
	all of the vendor modules supported by a device.</t>
        <t>Tags can also be used to help coordination when multiple multiple,
	semi-independent clients are interacting with the same devices. For
	example, one management client could mark that some modules should not
	be used because they have not been verified to behave correctly, so
	that other management clients avoid querying the data associated with
	those modules.</t>
        <t>Tag classification is useful for users searching module
	repositories (e.g., YANG catalog). A query restricted to the
	'ietf:routing' module tag could be used to return only the IETF YANG
	modules associated with routing. Without tags, a user would need to
	know the name of all the IETF routing protocol YANG modules.</t>
        <t>Future management protocol extensions could allow for filtering
	queries of configuration or operational state on a server based on
tags. For
	tags (for example, return all operational state related to
system-management.</t>
	system management).</t>
      </section>
      <section title="Conventions numbered="true" toc="default">
        <name>Conventions Used in This Document">
<t>The Document</name>
        <t>
    The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>",
    "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL
    NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>",
    "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
    "<bcp14>MAY</bcp14>", and
"OPTIONAL" "<bcp14>OPTIONAL</bcp14>" in this document are
    to be interpreted as
    described in BCP&nbsp;14 <xref target="RFC2119"/> <xref target="RFC8174"/>
    when, and only when, they appear in all capitals, as shown here.</t> here.
        </t>
      </section>
    </section>
    <section title="Tag Values"> numbered="true" toc="default">
      <name>Tag Values</name>
      <t>All tags SHOULD <bcp14>SHOULD</bcp14> begin with a prefix indicating who
      owns their definition. An IANA registry (<xref target="sec-yang-module-tag-prefixes-registry"></xref>)
      target="sec-yang-module-tag-prefixes-registry" format="default"/>) is
      used to support registering tag prefixes. Currently 3 Currently, three prefixes are
      defined. No further structure is imposed by this document on the value
      following the registered prefix, and the value can contain any YANG type
      'string' characters except carriage-returns, newlines carriage returns, newlines, and tabs.</t>
      <t>Again, except for the conflict-avoiding prefix, this document is
      purposefully not specifying any structure on (i.e., restricting) the tag values on
purpose. values.
      The intent is to avoid arbitrarily restricting the values that
      designers, implementers implementers, and users can use. As a result of this choice,
      designers, implementers, and users are free to add or not add any
      structure they may require to their own tag values.</t>
      <section title="IETF Tags" anchor="sec-ietf-tags"> anchor="sec-ietf-tags" numbered="true" toc="default">
        <name>IETF Tags</name>
        <t>An IETF tag is a tag that has the prefix "ietf:". All IETF tags are
	registered with IANA in a registry defined later in this document
	(<xref target="sec-ietf-yang-module-tags-registry"></xref>).</t> target="sec-ietf-yang-module-tags-registry"
	format="default"/>).</t>
      </section>
      <section title="Vendor Tags"> numbered="true" toc="default">
        <name>Vendor Tags</name>
        <t>A vendor tag is a tag that has the prefix "vendor:". These tags are
	defined by the vendor that implements the module, module and are not
	registered; however, it is RECOMMENDED <bcp14>RECOMMENDED</bcp14> that the vendor
	include extra identification in the tag to avoid collisions collisions, such as
	using the
enterpise enterprise or organization name following the "vendor:"
	prefix (e.g., vendor:example.com:vendor-defined-classifier).</t>
      </section>
      <section title="User Tags"> numbered="true" toc="default">
        <name>User Tags</name>
        <t>A user tag is any tag that has the prefix "user:". These tags are
	defined by the user/administrator and are not meant to be
	registered. Users are not required to use the "user:" prefix; however,
	doing so is RECOMMENDED <bcp14>RECOMMENDED</bcp14> as it helps avoid
	collisions.</t>
      </section>
      <section title="Reserved Tags"> numbered="true" toc="default">
        <name>Reserved Tags</name>
        <t>Any tag not starting with the prefix "ietf:", "vendor:" "vendor:", or "user:"
	is reserved for future use. These tag values are not invalid, invalid but
	simply reserved in the context of specifications (e.g., RFCs).</t>
      </section>
    </section>
    <section title="Tag Management"> numbered="true" toc="default">
      <name>Tag Management</name>
      <t>Tags can become associated with a module in a number of ways. Tags
      may be defined and associated at module design time, at implementation
      time, or via user administrative control. As the main consumer of tags
      are users, users may also remove any tag, no matter how the tag became
      associated with a module.</t>
      <section title="Module numbered="true" toc="default">
        <name>Module Definition Tagging"> Tagging</name>
        <t>A module definition MAY <bcp14>MAY</bcp14> indicate a set of tags to be
	added by the module implementer. These design time design-time tags are indicated
	using the module-tag extension statement.</t>
        <t>If the module is defined in an IETF standards track Standards Track document, the
	tags MUST <bcp14>MUST</bcp14> be <xref format="counter" target="sec-ietf-tags">IETF Tags</xref>. IETF Tags (<xref
	target="sec-ietf-tags"/>). Thus, new modules can drive
	the addition of new IETF tags to the IANA registry defined in <xref target="sec-ietf-yang-module-tags-registry"></xref>,
	target="sec-ietf-yang-module-tags-registry" format="default"/>, and
	the IANA registry can serve as a check against duplication.</t>
      </section>
      <section title="Implementation Tagging"> numbered="true" toc="default">
        <name>Implementation Tagging</name>
        <t>An implementation MAY <bcp14>MAY</bcp14> include additional tags
	associated with a module. These tags SHOULD <bcp14>SHOULD</bcp14> be IETF
	Tags (i.e., registered) or vendor
specific vendor-specific tags.</t>
      </section>
      <section title="User Tagging"> numbered="true" toc="default">
        <name>User Tagging</name>
        <t>Tags of any kind, with or without a prefix, can be assigned and
	removed by the user using normal configuration mechanisms. In order to
	remove a tag from the operational datastore datastore, the user adds a matching <spanx style='verb'>masked-tag</spanx>
	<tt>masked-tag</tt> entry for a given module.</t>
      </section>
    </section>
    <section title="Tags numbered="true" toc="default">
      <name>Tags Module Structure"> Structure</name>
      <section title="Tags numbered="true" toc="default">
        <name>Tags Module Tree"> Tree</name>
        <t>The tree associated with the "ietf-module-tags" module follows. The
	meaning of the symbols can be found in <xref target="RFC8340"/>.</t> target="RFC8340"
	format="default"/>.</t>
        <figure title="YANG anchor="sec-yang-module-tags-tree-diagram">
          <name>YANG Module Tags Tree Diagram" anchor="sec-yang-module-tags-tree-diagram"><artwork><![CDATA[ Diagram</name>
<sourcecode type="yangtree">
<![CDATA[
    module: ietf-module-tags
      +--rw module-tags
         +--rw module* [name]
            +--rw name          yang:yang-identifier
            +--rw tag*          tag
            +--rw masked-tag*   tag
]]></artwork></figure>
]]>
</sourcecode>
        </figure>
      </section>
      <section title="YANG Module"> numbered="true" toc="default">
        <name>YANG Module</name>
        <figure title="Module anchor="sec-module-tags-module">
          <name>Module Tags Module" anchor="sec-module-tags-module"><artwork><![CDATA[
<CODE BEGINS> file "ietf-module-tags@2020-02-29.yang" Module</name>
          <sourcecode name="ietf-module-tags@2020-08-05.yang" type="yang" markers="true"><![CDATA[
module ietf-module-tags {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-module-tags";
  prefix tags;

  import ietf-yang-types {
    prefix yang;
  }

  organization
    "IETF NetMod Working Group (NetMod)";
  contact
    "WG Web:  <https://tools.ietf.org/wg/netmod/>  <https://datatracker.ietf.org/wg/netmod/>
     WG List: <mailto:netmod@ietf.org>

     Author: Christian Hopps
             <mailto:chopps@chopps.org>

     Author: Lou Berger
	     <mailto:lberger@labn.net>
             <mailto:berger@labn.net>

     Author: Dean Bogdanovic
	     <ivandean@gmail.com>";

  // RFC Ed.: replace XXXX with actual RFC number and
  // remove this note.
             <mailto:ivandean@gmail.com>";

  description
    "This module describes a mechanism associating tags with YANG
     modules.  Tags may be IANA assigned or privately defined.

     Copyright (c) 2019 2020 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
     (https://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC XXXX
     (https://www.rfc-editor.org/info/rfcXXXX); 8819
     (https://www.rfc-editor.org/info/rfc8819); see the RFC itself
     for full legal notices.

     The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
     NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
     'MAY', and 'OPTIONAL' in this document are to be interpreted as
     described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
     they appear in all capitals, as shown here.";

  // RFC Ed.: update the date below with the date of RFC publication
  // and RFC number and remove this note.

  revision 2020-02-29 2020-08-05 {
    description
      "Initial revision.";
    reference
      "RFC XXXX: 8819: YANG Module Tags";
  }

  typedef tag {
    type string {
      length "1..max";
      pattern '[\S ]+';
    }
    description
      "A tag is a type of 'string' value that does not include
       carriage return, newline newline, or tab characters.  It SHOULD begin
       with a registered prefix; however, tags without a registered
       prefix SHOULD NOT be treated as invalid.";
  }

  extension module-tag {
    argument tag;
    description
      "The argument 'tag' is of type 'tag'.  This extension statement
       is used by module authors to indicate the tags that SHOULD be
       added automatically by the system.  As such such, the origin of the
       value for the pre-defined predefined tags should be set to 'system'
       [RFC8342].";
  }

  container module-tags {
    description
      "Contains the list of modules and their associated tags"; tags.";
    list module {
      key "name";
      description
        "A list of modules and their associated tags"; tags.";
      leaf name {
        type yang:yang-identifier;
        mandatory true;
        description
          "The YANG module name.";
      }
      leaf-list tag {
        type tag;
        description
          "Tags associated with the module.  See the IANA 'YANG
           Module Tag Prefixes' registry for reserved prefixes and
           the IANA 'IETF YANG Module Tags' registry for IETF tags.

           The 'operational' state [RFC8342] view of this list is
           constructed using the following steps:

           1) System tags (i.e., tags of 'system' origin) are added.
           2) User configured User-configured tags (i.e., tags of 'intended' origin)
           are added.
           3) Any tag that is equal to a masked-tag is removed.";
      }
      leaf-list masked-tag {
        type tag;
        description
          "The list of tags that should not be associated with this
           module.  The user can remove (mask) tags from the
           operational state datastore [RFC8342] by adding them to
           this list.  It is not an error to add tags to this list
           that are not associated with the module, but they have no
           operational effect.";
      }
    }
  }
}
<CODE ENDS>
]]></artwork></figure>
]]>
</sourcecode>
        </figure>
      </section>
    </section>
    <section title="Other Classifications"> numbered="true" toc="default">
      <name>Other Classifications</name>
      <t>It is worth noting that a different YANG module classification
      document exists <xref target="RFC8199"/>. target="RFC8199" format="default"/>. That document
      only classifies modules in a logical manner and does not define tagging
      or any other mechanisms. It divides YANG modules into two categories
      (service or element) and then into one of three origins: standard, vendor
      vendor, or user. It does provide a good way to discuss and identify
      modules in general. This document defines IETF tags to support <xref target="RFC8199"/> the
      classification style
classification.</t> described in <xref target="RFC8199" format="default"/>.</t>
    </section>
    <section title="Guidelines anchor="sec-guidelines-to-model-writers" numbered="true" toc="default">
      <name>Guidelines to Model Writers" anchor="sec-guidelines-to-model-writers"> Writers</name>
      <t>This section updates <xref target="RFC8407"/>.</t> target="RFC8407" format="default"/>.</t>
      <section title="Define numbered="true" toc="default">
        <name>Define Standard Tags"> Tags</name>
        <t>A module MAY <bcp14>MAY</bcp14> indicate, using module-tag extension
	statements, a set of tags that are to be automatically associated with
	it (i.e., not added through configuration).</t>

<figure><artwork><![CDATA[
<!-- [rfced] Section 6.1: Note that we have marked the following as
<sourcecode> instead of of <artwork>.  Please review and let us know if this
is incorrect. If <sourcecode> is correct, should type be set to yang?

Orignal:
   module example-module {
     //...
     import module-tags { prefix tags; }

     tags:module-tag "ietf:some-new-tag";
     tags:module-tag "ietf:some-other-tag";
     // ...
   }

-->

<sourcecode name="" type=""><![CDATA[
module example-module {
  //...
  import module-tags { prefix tags; }

  tags:module-tag "ietf:some-new-tag";
  tags:module-tag "ietf:some-other-tag";
  // ...
}
]]></artwork></figure>
]]></sourcecode>
        <t>The module writer can use existing standard tags, tags or use new tags
	defined in the model definition, as appropriate. For IETF standardized modules
	modules, new tags MUST <bcp14>MUST</bcp14> be assigned in the IANA registry
	defined below, see <xref target="sec-ietf-yang-module-tags-registry"></xref>.</t> target="sec-ietf-yang-module-tags-registry"
	format="default"/>.</t>
      </section>
    </section>
    <section title="IANA Considerations"> numbered="true" toc="default">
      <name>IANA Considerations</name>
      <section title="YANG anchor="sec-yang-module-tag-prefixes-registry" numbered="true"
	       toc="default">
        <name>YANG Module Tag Prefixes Registry" anchor="sec-yang-module-tag-prefixes-registry"> Registry</name>
        <t>IANA is asked to create a new registry has created the "YANG Module Tag Prefixes"
grouped under a new "Protocol" category named subregistry
	in the "YANG Module Tags".</t> Tags" registry.</t>
        <t>This registry allocates tag prefixes. All YANG module tags SHOULD
	<bcp14>SHOULD</bcp14> begin with one of the prefixes in this registry.</t>
        <t>Prefix entries in this registry should be short strings consisting
	of lowercase ASCII alpha-numeric characters and a final ":" character.</t>
        <t>The allocation policy for this registry is Specification Required
	<xref target="RFC8126"/>. target="RFC8126" format="default"/>. The Reference and Assignee
	values should be sufficient to identify and contact the organization
	that has been allocated the prefix.</t>
        <t>The initial values for this registry are as follows.</t>

<texttable>
<ttcol>Prefix</ttcol><ttcol>Description</ttcol><ttcol>Reference</ttcol><ttcol>Assignee</ttcol>
<c>ietf:</c><c>IETF

        <table align="center">
          <thead>
            <tr>
              <th align="left">Prefix</th>
              <th align="left">Description</th>
              <th align="left">Reference</th>
              <th align="left">Assignee</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td align="left">ietf:</td>
              <td align="left">IETF Tags allocated in the IANA IETF "IETF YANG
	      Module Tags registry.</c><c>[This document]</c><c>IETF</c>
<c>vendor:</c><c>Non-registered Tags" registry.</td>
              <td align="left">RFC 8819</td>
              <td align="left">IETF</td>
            </tr>
            <tr>
              <td align="left">vendor:</td>
              <td align="left">Non-registered tags allocated by the module implementer.</c><c>[This document]</c><c>IETF</c>
<c>user:</c><c>Non-registered
	      implementer.</td>
              <td align="left">RFC 8819</td>
              <td align="left">IETF</td>
            </tr>
            <tr>
              <td align="left">user:</td>
              <td align="left">Non-registered tags allocated by and for the user.</c><c>[This document]</c><c>IETF</c>
</texttable>
	      user.</td>
              <td align="left">RFC 8819</td>
              <td align="left">IETF</td>
            </tr>
          </tbody>
        </table>
        <t>Other standards development organizations (SDOs) wishing to
	allocate their own set of tags should allocate a prefix from this
	registry.</t>
      </section>
      <section title="IETF anchor="sec-ietf-yang-module-tags-registry" numbered="true"
	       toc="default">
        <name>IETF YANG Module Tags Registry" anchor="sec-ietf-yang-module-tags-registry"> Registry</name>
        <t>IANA is asked to create a new registry has created the "IETF YANG Module Tags" grouped
under a new "Protocol" category "IETF YANG subregistry
	within the "YANG Module Tags". Tags" registry . This
	registry
should be included appears below the "YANG Module Tag Prefixes" when listed on
the same page.</t> registry.</t>
        <t>This registry allocates tags that have the registered prefix
	"ietf:". New values should be well considered and not achievable
	through a combination of already existing IETF tags. IANA assigned
	tags must conform to Net-Unicode as defined in <xref target="RFC5198"/> target="RFC5198"
	format="default"/>, and they shall not need normalization.</t>
        <t>The allocation policy for this registry is IETF Review <xref target="RFC8126"/>.</t>
	target="RFC8126" format="default"/>.</t>
        <t>The initial values for this registry are as follows.</t>

<texttable>
<ttcol>Tag</ttcol><ttcol>Description</ttcol><ttcol>Reference</ttcol>
<c>ietf:network-element-class</c><c><xref target="RFC8199"/> network element.</c><c><xref target="RFC8199"/></c>
<c>ietf:network-service-class</c><c><xref target="RFC8199"/> network service.</c><c><xref target="RFC8199"/></c>
<c>ietf:sdo-defined-class</c><c>Module

        <table align="center">
          <thead>
            <tr>
              <th align="left">Tag</th>
              <th align="left">Description</th>
              <th align="left">Reference</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td align="left">ietf:network-element-class</td>
              <td align="left">Network element as defined in
                <xref target="RFC8199" format="default"/>.</td>
              <td align="left">
                <xref target="RFC8199" format="default"/></td>
            </tr>
            <tr>
              <td align="left">ietf:network-service-class</td>
              <td align="left">Network service as defined in
                <xref target="RFC8199" format="default"/>.</td>
              <td align="left">
                <xref target="RFC8199" format="default"/></td>
            </tr>
            <tr>
              <td align="left">ietf:sdo-defined-class</td>
              <td align="left">Module is defined by a standards organization.</c><c><xref target="RFC8199"/></c>
<c>ietf:vendor-defined-class</c><c>Module organization.</td>
              <td align="left">
                <xref target="RFC8199" format="default"/></td>
            </tr>
            <tr>
              <td align="left">ietf:vendor-defined-class</td>
              <td align="left">Module is defined by a vendor.</c><c><xref target="RFC8199"/></c>
<c>ietf:user-defined-class</c><c>Module vendor.</td>
              <td align="left">
                <xref target="RFC8199" format="default"/></td>
            </tr>
            <tr>
              <td align="left">ietf:user-defined-class</td>
              <td align="left">Module is defined by the user.</c><c><xref target="RFC8199"/></c>
<c>ietf:hardware</c><c>Relates user.</td>
              <td align="left">
                <xref target="RFC8199" format="default"/></td>
            </tr>
            <tr>
              <td align="left">ietf:hardware</td>
              <td align="left">Relates to hardware (e.g., inventory).</c><c>[This document]</c>
<c>ietf:software</c><c>Relates inventory).</td>
              <td align="left">RFC 8819</td>
            </tr>
            <tr>
              <td align="left">ietf:software</td>
              <td align="left">Relates to software (e.g., installed OS).</c><c>[This document]</c>
<c>ietf:protocol</c><c>Represents OS).</td>
              <td align="left">RFC 8819</td>
            </tr>
            <tr>
              <td align="left">ietf:protocol</td>
              <td align="left">Represents a protocol (often combined with
	      another tag to refine).</c><c>[This document]</c>
<c>ietf:qos</c><c>Relates refine).</td>
              <td align="left">RFC 8819</td>
            </tr>
            <tr>
              <td align="left">ietf:qos</td>
              <td align="left">Relates to quality of service.</c><c>[This document]</c>
<c>ietf:network-service-app</c><c>Relates service.</td>
              <td align="left">RFC 8819</td>
            </tr>
            <tr>
              <td align="left">ietf:network-service-app</td>
              <td align="left">Relates to a network service application (e.g.,
	      an NTP server, DNS server, DHCP server, etc).</c><c>[This document]</c>
<c>ietf:system-management</c><c>Relates etc.).</td>
              <td align="left">RFC 8819</td>
            </tr>
            <tr>
              <td align="left">ietf:system-management</td>
<!-- [IANA] ask IANA to update this entry to use "etc" instead of ellipses -
similar to entry for ietf:network-service-app.
-->
              <td align="left">Relates to system management (e.g., a system
	      management protocol such as syslog, TACAC+, SNMP, netconf, ...).</c><c>[This document]</c>
<c>ietf:oam</c><c>Relates NETCONF, etc.).</td>
              <td align="left">RFC 8819</td>
            </tr>
            <tr>
              <td align="left">ietf:oam</td>
              <td align="left">Relates to Operations, Administration, and
	      Maintenance (e.g., BFD).</c><c>[This document]</c>
<c>ietf:routing</c><c>Relates to routing.</c><c>[This document]</c>
<c>ietf:security</c><c>Related to security.</c><c>[This document]</c>
<c>ietf:signaling</c><c>Relates to control plane signaling.</c><c>[This document]</c>
<c>ietf:link-management</c><c>Relates BFD).</td>
              <td align="left">RFC 8819</td>
            </tr>
            <tr>
              <td align="left">ietf:routing</td>
              <td align="left">Relates to routing.</td>
              <td align="left">RFC 8819</td>
            </tr>
            <tr>
              <td align="left">ietf:security</td>
              <td align="left">Related to security.</td>
              <td align="left">RFC 8819</td>
            </tr>
<!-- [IANA] ask IANA to add the hyphen for "control-plane" -->
            <tr>
              <td align="left">ietf:signaling</td>
              <td align="left">Relates to control-plane signaling.</td>
              <td align="left">RFC 8819</td>
            </tr>
            <tr>
              <td align="left">ietf:link-management</td>
              <td align="left">Relates to link management.</c><c>[This document]</c>
</texttable> management.</td>
              <td align="left">RFC 8819</td>
            </tr>
          </tbody>
        </table>
      </section>
      <section title="Updates numbered="true" toc="default">
        <name>Updates to the IETF XML Registry"> Registry</name>
        <t>This document registers a URI in the "IETF XML Registry" <xref target="RFC3688"/>.
	target="RFC3688" format="default"/>. Following the format in <xref target="RFC3688"/>,
	target="RFC3688" format="default"/>, the following registrations have
	been made:</t>

<t><list style="hanging">
<t hangText="URI:"><vspace/>urn:ietf:params:xml:ns:yang:ietf-module-tags</t>
<t hangText="Registrant Contact:"><vspace/>The IESG.</t>
<t hangText="XML:"><vspace/>N/A;
        <dl newline="false" spacing="compact">
          <dt>URI:</dt>
          <dd>urn:ietf:params:xml:ns:yang:ietf-module-tags</dd>
          <dt>Registrant Contact:</dt>
          <dd>The IESG.</dd>
          <dt>XML:</dt>
          <dd>N/A; the requested URI is an XML namespace.</t>

<t hangText="URI:"><vspace/>urn:ietf:params:xml:ns:yang:ietf-module-tags-state</t>
<t hangText="Registrant Contact:"><vspace/>The IESG.</t>
<t hangText="XML:"><vspace/>N/A; namespace.</dd>
	</dl>
	<dl newline="false" spacing="compact">
          <dt>URI:</dt>
          <dd>urn:ietf:params:xml:ns:yang:ietf-module-tags-state</dd>
          <dt>Registrant Contact:</dt>
          <dd>The IESG.</dd>
          <dt>XML:</dt>
          <dd>N/A; the requested URI is an XML namespace.</t>
</list></t> namespace.</dd>
        </dl>
      </section>
      <section title="Updates numbered="true" toc="default">
        <name>Updates to the YANG Module Names Registry"> Registry</name>
        <t>This document registers two YANG modules in the "YANG Module Names"
	registry <xref target="RFC6020"/>. target="RFC6020" format="default"/>. Following the
	format in <xref target="RFC6020"/>, target="RFC6020" format="default"/>, the following
registration
	registrations have been made:</t>

<t><list style="hanging">
<t hangText="name:"><vspace/>ietf-module-tags</t>
<t hangText="namespace:"><vspace/>urn:ietf:params:xml:ns:yang:ietf-module-tags</t>
<t hangText="prefix:"><vspace/>tags</t>
<t hangText="reference:"><vspace/>RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove this note.)</t>

<t hangText="name:"><vspace/>ietf-module-tags-state</t>
<t hangText="namespace:"><vspace/>urn:ietf:params:xml:ns:yang:ietf-module-tags-state</t>
<t hangText="prefix:"><vspace/>tags</t>
<t hangText="reference:"><vspace/>RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove this note.)</t>
</list></t>

</section>

</section>

<section title="Security Considerations">
<t>The YANG module defined in this memo is designed to be accessed
        <dl newline="false" spacing="compact">
          <dt>name:</dt>
          <dd>ietf-module-tags</dd>
          <dt>namespace:</dt>
          <dd>urn:ietf:params:xml:ns:yang:ietf-module-tags</dd>
          <dt>prefix:</dt>
          <dd>tags</dd>
          <dt>reference:</dt>
          <dd>RFC 8819</dd>
	</dl>
<!-- [rfced] For the ietf-module-tags-state registration, IANA shows the
prefix as "tags-s".  In addition, also uses "prefix tags-s;".  Should the
IANA entry be updated to match?

Current:
   name:  ietf-module-tags-state
   namespace:  urn:ietf:params:xml:ns:yang:ietf-module-tags-state
   prefix:  tags
   reference:  RFC 8819
-->

	<dl newline="false" spacing="compact">
          <dt>name:</dt>
          <dd>ietf-module-tags-state</dd>
          <dt>namespace:</dt>
          <dd>urn:ietf:params:xml:ns:yang:ietf-module-tags-state</dd>
          <dt>prefix:</dt>
          <dd>tags</dd>
          <dt>reference:</dt>
          <dd>RFC 8819</dd>
        </dl>
      </section>
    </section>
    <section numbered="true" toc="default">
      <name>Security Considerations</name>
      <t>The YANG module defined in this memo is designed to be accessed via
      the NETCONF protocol <xref target="RFC6241"/>. target="RFC6241" format="default"/>. The
      lowest NETCONF layer is the secure transport layer and the
      mandatory-to-implement secure transport is SSH <xref target="RFC6242"/>.</t>

<t>This document adds the ability to associate tag meta-data with YANG
modules. This document does not define any actions based on these
associations, and none are yet defined, and therefore it does not
by itself introduce any new security considerations directly.</t>

<t>Users of the tag-meta data may define various actions to be taken
based on the tag meta-data. These actions and their definitions are
outside the scope of this document. Users will need to consider the
security implications of any actions they choose to define,
including the potential for a tag to get 'masked' by another user.</t>

</section>

</middle>
<back>
<references title="Normative References">

<reference  anchor='RFC2119' target='https://www.rfc-editor.org/info/rfc2119'>
<front>
<title>Key words for use in RFCs to Indicate Requirement Levels</title>
<author initials='S.' surname='Bradner' fullname='S. Bradner'><organization /></author>
<date year='1997' month='March' />
<abstract><t>In many standards track documents several words are used to signify the requirements in the specification.  These words are often capitalized. This document defines these words as they should be interpreted in IETF documents.  This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t></abstract>
</front>
<seriesInfo name='BCP' value='14'/>
<seriesInfo name='RFC' value='2119'/>
<seriesInfo name='DOI' value='10.17487/RFC2119'/>
</reference>

<reference  anchor='RFC7950' target='https://www.rfc-editor.org/info/rfc7950'>
<front>
<title>The YANG 1.1 Data Modeling Language</title>
<author initials='M.' surname='Bjorklund' fullname='M. Bjorklund' role='editor'><organization /></author>
<date year='2016' month='August' />
<abstract><t>YANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols.  This document describes the syntax and semantics of version 1.1 of the YANG language.  YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification.  There are a small number of backward incompatibilities from YANG version 1.  This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF).</t></abstract>
</front>
<seriesInfo name='RFC' value='7950'/>
<seriesInfo name='DOI' value='10.17487/RFC7950'/>
</reference>

<reference  anchor='RFC8126' target='https://www.rfc-editor.org/info/rfc8126'>
<front>
<title>Guidelines for Writing an IANA Considerations Section in RFCs</title>
<author initials='M.' surname='Cotton' fullname='M. Cotton'><organization /></author>
<author initials='B.' surname='Leiba' fullname='B. Leiba'><organization /></author>
<author initials='T.' surname='Narten' fullname='T. Narten'><organization /></author>
<date year='2017' month='June' />
<abstract><t>Many protocols make use of points of extensibility that use constants to identify various protocol parameters.  To ensure that the values in these fields do not have conflicting uses and to promote interoperability, their allocations are often coordinated by a central record keeper.  For IETF protocols, that role is filled by the Internet Assigned Numbers Authority (IANA).</t><t>To make assignments in a given registry prudently, guidance describing the conditions under which new values should be assigned, as well as when and how modifications to existing values can be made, is needed.  This document defines a framework for the documentation of these guidelines by specification authors, in order to assure that the provided guidance for the IANA Considerations is clear and addresses the various issues that are likely in the operation of a registry.</t><t>This is the third edition of this document; it obsoletes RFC 5226.</t></abstract>
</front>
<seriesInfo name='BCP' value='26'/>
<seriesInfo name='RFC' value='8126'/>
<seriesInfo name='DOI' value='10.17487/RFC8126'/>
</reference>

<reference  anchor='RFC8174' target='https://www.rfc-editor.org/info/rfc8174'>
<front>
<title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title>
<author initials='B.' surname='Leiba' fullname='B. Leiba'><organization /></author>
<date year='2017' month='May' />
<abstract><t>RFC 2119 specifies common key words that may be used in protocol  specifications.  This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the  defined special meanings.</t></abstract>
</front>
<seriesInfo name='BCP' value='14'/>
<seriesInfo name='RFC' value='8174'/>
<seriesInfo name='DOI' value='10.17487/RFC8174'/>
</reference>

<reference  anchor='RFC8342' target='https://www.rfc-editor.org/info/rfc8342'>
<front>
<title>Network Management Datastore Architecture (NMDA)</title>
<author initials='M.' surname='Bjorklund' fullname='M. Bjorklund'><organization /></author>
<author initials='J.' surname='Schoenwaelder' fullname='J. Schoenwaelder'><organization /></author>
<author initials='P.' surname='Shafer' fullname='P. Shafer'><organization /></author>
<author initials='K.' surname='Watsen' fullname='K. Watsen'><organization /></author>
<author initials='R.' surname='Wilton' fullname='R. Wilton'><organization /></author>
<date year='2018' month='March' />
<abstract><t>Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model.  This document updates RFC 7950.</t></abstract>
</front>
<seriesInfo name='RFC' value='8342'/>
<seriesInfo name='DOI' value='10.17487/RFC8342'/>
</reference>

<reference  anchor='RFC8199' target='https://www.rfc-editor.org/info/rfc8199'>
<front>
<title>YANG Module Classification</title>
<author initials='D.' surname='Bogdanovic' fullname='D. Bogdanovic'><organization /></author>
<author initials='B.' surname='Claise' fullname='B. Claise'><organization /></author>
<author initials='C.' surname='Moberg' fullname='C. Moberg'><organization /></author>
<date year='2017' month='July' />
<abstract><t>The YANG data modeling language is currently being considered for a wide variety of applications throughout the networking industry at large.  Many standards development organizations (SDOs), open-source software projects, vendors, and users are using YANG to develop and publish YANG modules for a wide variety of applications.  At the same time, there is currently no well-known terminology to categorize various types of YANG modules.</t><t>A consistent terminology would help with the categorization of YANG modules, assist in the analysis of the YANG data modeling efforts in the IETF and other organizations, and bring clarity to the YANG- related discussions between the different groups.</t><t>This document describes a set of concepts and associated terms to support consistent classification of YANG modules.</t></abstract>
</front>
<seriesInfo name='RFC' value='8199'/>
<seriesInfo name='DOI' value='10.17487/RFC8199'/>
</reference>

<reference  anchor='RFC8407' target='https://www.rfc-editor.org/info/rfc8407'>
<front>
<title>Guidelines for Authors and Reviewers of Documents Containing YANG Data Models</title>
<author initials='A.' surname='Bierman' fullname='A. Bierman'><organization /></author>
<date year='2018' month='October' />
<abstract><t>This memo provides guidelines for authors and reviewers of specifications containing YANG modules.  Recommendations and procedures are defined, which are intended to increase interoperability and usability of Network Configuration Protocol (NETCONF) and RESTCONF protocol implementations that utilize YANG modules.  This document obsoletes RFC 6087.</t></abstract>
</front>
<seriesInfo name='BCP' value='216'/>
<seriesInfo name='RFC' value='8407'/>
<seriesInfo name='DOI' value='10.17487/RFC8407'/>
</reference>
</references>
<references title="Informative References">

<reference  anchor='RFC3688' target='https://www.rfc-editor.org/info/rfc3688'>
<front>
<title>The IETF XML Registry</title>
<author initials='M.' surname='Mealling' fullname='M. Mealling'><organization /></author>
<date year='2004' month='January' />
<abstract><t>This document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas.</t></abstract>
</front>
<seriesInfo name='BCP' value='81'/>
<seriesInfo name='RFC' value='3688'/>
<seriesInfo name='DOI' value='10.17487/RFC3688'/>
</reference>

<reference  anchor='RFC5198' target='https://www.rfc-editor.org/info/rfc5198'>
<front>
<title>Unicode Format for Network Interchange</title>
<author initials='J.' surname='Klensin' fullname='J. Klensin'><organization /></author>
<author initials='M.' surname='Padlipsky' fullname='M. Padlipsky'><organization /></author>
<date year='2008' month='March' />
<abstract><t>The Internet today is in need of a standardized form for the transmission of internationalized &quot;text&quot; information, paralleling the specifications for the use of ASCII that date from the early days of the ARPANET.  This document specifies that format, using UTF-8 with normalization and specific line-ending sequences.  [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='5198'/>
<seriesInfo name='DOI' value='10.17487/RFC5198'/>
</reference>

<reference  anchor='RFC6020' target='https://www.rfc-editor.org/info/rfc6020'>
<front>
<title>YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)</title>
<author initials='M.' surname='Bjorklund' fullname='M. Bjorklund' role='editor'><organization /></author>
<date year='2010' month='October' />
<abstract><t>YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='6020'/>
<seriesInfo name='DOI' value='10.17487/RFC6020'/>
</reference>

<reference  anchor='RFC6241' target='https://www.rfc-editor.org/info/rfc6241'>
<front>
<title>Network Configuration Protocol (NETCONF)</title>
<author initials='R.' surname='Enns' fullname='R. Enns' role='editor'><organization /></author>
<author initials='M.' surname='Bjorklund' fullname='M. Bjorklund' role='editor'><organization /></author>
<author initials='J.' surname='Schoenwaelder' fullname='J. Schoenwaelder' role='editor'><organization /></author>
<author initials='A.' surname='Bierman' fullname='A. Bierman' role='editor'><organization /></author>
<date year='2011' month='June' />
<abstract><t>The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices.  It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages.  The NETCONF protocol operations are realized as remote procedure calls (RPCs).  This document obsoletes RFC 4741.  [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='6241'/>
<seriesInfo name='DOI' value='10.17487/RFC6241'/>
</reference>

<reference  anchor='RFC6242' target='https://www.rfc-editor.org/info/rfc6242'>
<front>
<title>Using the NETCONF Protocol over Secure Shell (SSH)</title>
<author initials='M.' surname='Wasserman' fullname='M. Wasserman'><organization /></author>
<date year='2011' month='June' />
<abstract><t>This document describes a method for invoking and running the Network Configuration Protocol (NETCONF) within a Secure Shell (SSH) session as an SSH subsystem.  This document obsoletes RFC 4742.  [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='6242'/>
<seriesInfo name='DOI' value='10.17487/RFC6242'/>
</reference>

<reference  anchor='RFC8340' target='https://www.rfc-editor.org/info/rfc8340'>
<front>
<title>YANG Tree Diagrams</title>
<author initials='M.' surname='Bjorklund' fullname='M. Bjorklund'><organization /></author>
<author initials='L.' surname='Berger' fullname='L. Berger' role='editor'><organization /></author>
<date year='2018' month='March' />
<abstract><t>This document captures the current syntax used in YANG module tree diagrams.  The purpose of this Shell (SSH) <xref
      target="RFC6242" format="default"/>.</t>
      <t>This document is adds the ability to provide a single location for this definition. associate tag metadata with YANG
      modules. This syntax document does not define any actions based on these
      associations, and none are yet defined; therefore, it does not by
      itself introduce any new security considerations directly.</t>
      <t>Users of the tag metadata may be updated from time define various actions to time be taken
      based on the evolution tag metadata. These actions and their definitions are
      outside the scope of this document. Users will need to consider the YANG language.</t></abstract>
</front>
<seriesInfo name='BCP' value='215'/>
<seriesInfo name='RFC' value='8340'/>
<seriesInfo name='DOI' value='10.17487/RFC8340'/>
</reference>
      security implications of any actions they choose to define, including
      the potential for a tag to get 'masked' by another user.</t>
    </section>
  </middle>
  <back>
    <references>
      <name>References</name>
      <references>
        <name>Normative References</name>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.7950.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8126.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8342.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8199.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8407.xml"/>
      </references>
      <references>
        <name>Informative References</name>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.3688.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.5198.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.6020.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.6241.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.6242.xml"/>
        <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8340.xml"/>
      </references>
    </references>
    <section title="Examples"> numbered="true" toc="default">
      <name>Examples</name>
      <t>The following is a fictional NETCONF example result from a query of
      the module tags list. For the sake of brevity brevity, only a few module results
      are imagined.</t> shown.</t>
      <figure title="Example anchor="sec-example-netconf-query-output">
        <name>Example NETCONF Query Output</name>

<!--[rfced] The second line in the figure "Example NETCONF Query Output" anchor="sec-example-netconf-query-output"><artwork><![CDATA[
exceeds the 72-character limit. Please review and let us know how this line
should be altered.

123456789012345678901234567890123456789012345678901234567890123456789012
     <t:module-tags xmlns:t="urn:ietf:params:xml:ns:yang:ietf-module-tags">

-->
        <sourcecode type="xml"><![CDATA[
<ns0:data xmlns:ns0="urn:ietf:params:xml:ns:netconf:base:1.0">
  <t:module-tags xmlns:t="urn:ietf:params:xml:ns:yang:ietf-module-tags">
    <t:module>
      <t:name>ietf-bfd</t:name>
      <t:tag>ietf:network-element-class</t:tag>
      <t:tag>ietf:oam</t:tag>
      <t:tag>ietf:protocol</t:tag>
      <t:tag>ietf:sdo-defined-class</t:tag>
    </t:module>
    <t:module>
      <t:name>ietf-isis</t:name>
      <t:tag>ietf:network-element-class</t:tag>
      <t:tag>ietf:protocol</t:tag>
      <t:tag>ietf:sdo-defined-class</t:tag>
      <t:tag>ietf:routing</t:tag>
    </t:module>
    <t:module>
      <t:name>ietf-ssh-server</t:name>
      <t:tag>ietf:network-element-class</t:tag>
      <t:tag>ietf:protocol</t:tag>
      <t:tag>ietf:sdo-defined-class</t:tag>
      <t:tag>ietf:system-management</t:tag>
    </t:module>
  </t:module-tags>
</ns0:data>
]]></artwork></figure>

</section>

<section title="Acknowledgements">
<t>Special thanks to Robert Wilton for his help improving the
introduction and providing the example use cases, as well as
generating the non-NMDA module.</t>
]]></sourcecode>

      </figure>
    </section>
    <section title="Non-NMDA numbered="true" toc="default">
      <name>Non-NMDA State Module."> Module.</name>
      <t>As per <xref target="RFC8407"/> target="RFC8407" format="default"/>, the following is a
      non-NMDA module to support viewing the operational state for non-NMDA
      compliant servers.</t>
      <figure title="Non-NMDA anchor="sec-non-nmda-module-tags-state-module">
        <name>Non-NMDA Module Tags State Module" anchor="sec-non-nmda-module-tags-state-module"><artwork><![CDATA[
<CODE BEGINS> file "ietf-module-tags-state@2020-02-29.yang" Module</name>
        <sourcecode name="ietf-module-tags-state@2020-08-05.yang" type="yang"
		    markers="true"><![CDATA[
module ietf-module-tags-state {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-module-tags-state";
  prefix tags-s;

  import ietf-yang-types {
    prefix yang;
  }
  import ietf-module-tags {
    prefix tags;
  }

  organization
    "IETF NetMod Working Group (NetMod)";
  contact
    "WG Web:  <https://tools.ietf.org/wg/netmod/>  <https://datatracker.ietf.org/wg/netmod/>
     WG List: <mailto:netmod@ietf.org>

     Author: Christian Hopps
             <mailto:chopps@chopps.org>

     Author: Lou Berger
             <mailto:lberger@labn.net>

     Author: Dean Bogdanovic
	     <ivandean@gmail.com>";

  // RFC Ed.: replace XXXX with actual RFC number and
  // remove this note.
             <mailto:ivandean@gmail.com>";

  description
    "This module describes a mechanism associating tags with YANG
     modules.  Tags may be IANA assigned or privately defined.

     This is a temporary non-NMDA module that is for use by
     implementations that don't yet support NMDA.

     Copyright (c) 2019 2020 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
     (https://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC XXXX
     (https://www.rfc-editor.org/info/rfcXXXX); 8819
     (https://www.rfc-editor.org/info/rfc8819); see the RFC itself
     for full legal notices.

     The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
     NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
     'MAY', and 'OPTIONAL' in this document are to be interpreted as
     described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
     they appear in all capitals, as shown here.";

  // RFC Ed.: update the date below with the date of RFC publication
  // and RFC number and remove this note. notices.";

  revision 2020-02-29 2020-08-05 {
    description
      "Initial revision.";
    reference
      "RFC XXXX: 8819: YANG Module Tags";
  }

  container module-tags-state {
    config false;
    status deprecated;
    description
      "Contains the list of modules and their associated tags"; tags.";
    list module {
      key "name";
      status deprecated;
      description
        "A list of modules and their associated tags"; tags.";
      leaf name {
        type yang:yang-identifier;
        mandatory true;
        status deprecated;
        description
          "The YANG module name.";
      }
      leaf-list tag {
        type tags:tag;
        status deprecated;
        description
          "Tags associated with the module.  See the IANA 'YANG
           Module Tag Prefixes' registry for reserved prefixes and
           the IANA 'IETF YANG Module Tags' registry for IETF tags.

           The contents of this list is constructed using the
           following steps:

           1) System tags (i.e., tags of added by the system) are
           added.
           2) User configured User-configured tags (i.e., tags added by
           configuration) are added.
           3) Any tag that is equal to a masked-tag present in the
           corresponding ietf-module-tags:module-tags:module-tag leaf
           list for this module is removed.";
      }
    }
  }
}
<CODE ENDS>
]]></artwork></figure>
]]></sourcecode>
      </figure>
    </section>
    <section numbered="false" toc="default">
      <name>Acknowledgements</name>
      <t>Special thanks to <contact fullname="Robert Wilton"/> for his help
      improving the introduction and providing the example use cases, as well
      as generating the non-NMDA module.</t>
    </section>
  </back>
<!--[rfced] Throughout the text, the following terminology appears to be used
inconsistently. Please review and let us know if/how they may be made
consistent.

IETF Tag vs. IETF tag
-->
</rfc>