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<?rfc tocdepth="2"?>
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<rfc category="std"
     docName="draft-ietf-netconf-yang-notifications-versioning-09"
     ipr="trust200902" submissionType="IETF" consensus="true">
  <front>
    <title abbrev="YANG Notifications Versioning">Support of Versioning
    in YANG Notifications Subscription</title>

    <author fullname="Thomas Graf" initials="T" surname="Graf">
      <organization>Swisscom</organization>

      <address>
        <postal>
          <street>Binzring 17</street>

          <city>Zurich</city>

          <code>8045</code>

          <country>Switzerland</country>
        </postal>

        <email>thomas.graf@swisscom.com</email>
      </address>
    </author>

    <author fullname="Benoit Claise" initials="B" surname="Claise">
      <organization>Huawei</organization>

      <address>
        <email>benoit.claise@huawei.com</email>
      </address>
    </author>

    <author fullname="Alex Huang-Feng" initials="A." surname="Huang-Feng">
      <organization>INSA-Lyon</organization>

      <address>
        <postal>
          <street/>

          <city>Lyon</city>

          <region/>

          <code/>

          <country>France</country>
        </postal>

        <phone/>

        <facsimile/>

        <email>alex.huang-feng@insa-lyon.fr</email>

        <uri/>
      </address>
    </author>

    <date day="05" month="September" year="2025"/>

    <abstract>
      <t>This document extends the YANG notifications subscription
      mechanism to specify the YANG module semantic version at the
      subscription. Then, a new extension with the revision and the
      semantic version of the YANG-Push subscription state change
      notification is proposed.</t>
    </abstract>
  </front>

  <middle>
    <section anchor="Introduction" title="Introduction">
      <t>In order to process the newly received YANG-Push notification
      messages described in <xref section="3.7" sectionFormat="of"
      target="RFC8641"/> without querying the Publisher 
      IETF-YANG-LIBRARY each time to understand whether the
      YANG module(s) semantic has changed at the YANG-Push receiver, a
      semantic reference to the YANG module and the XPath or subtree is
      needed to determine the data types for each field and which part
      of the YANG module the metrics are expose from.</t>

      <t>This specification applies to the YANG-Push configured
      subscriptions defined in <xref section="2.5" sectionFormat="of"
      target="RFC8639"/>, where a publisher is configured to stream
      notification out of band, as opposed to dynamic subscriptions
      defined in <xref section="2.4" sectionFormat="of"
      target="RFC8639"/>, where the subscriber can initiate and modify
      the subscription dynamically in-band. In the latter case, the
      subscriber knows already all the subscriber YANG-related
      information, which it has to know in order to configure the
      subscription.</t>

      <t>This semantic reference is available when the subscription is
      established as described in <xref section="3.6" sectionFormat="of"
      target="RFC8641"/> and being streamed from the publisher to
      receiver with the subscription state change notifications
      described in <xref section="2.7" sectionFormat="of"
      target="RFC8639"/> where for each subscription a locally unique
      subscription ID described in <xref section="4.3.2"
      sectionFormat="of" target="RFC8641"/> is being issued and streamed
      as metadata with the notification message in the YANG-Push
      message header.</t>

      <t>The semantics can change between different YANG module
      revisions. The YANG module version statement is specified in
      <xref section="7.1.2" sectionFormat="of" target="RFC6020"/> and
      states that the newer revision needs to be backward compatible to
      the previous revision. <xref section="3.1" sectionFormat="of"
      target="I-D.ietf-netmod-yang-module-versioning"/> specifies that
      newer semantic versions introduced in <xref
      target="I-D.ietf-netmod-yang-semver"/> MAY not be backward
      compatible to the previous version when indicated with
      non-backwards-compatible keyword.</t>

      <t>The YANG notifications subscription mechanism defined in <xref
      target="RFC8641"/> does not allow to specify the YANG module
      revision. When a network node is upgraded, the subscribed YANG
      module revision MAY have updated and might, consequently, break
      the data processing pipeline since the YANG-Push receiver may not
      be aware of this change.</t>

      <t>This documents extends the current YANG notifications
      subscription mechanism to allow to subscribe to a specific
      revision or latest YANG module semantic version to which the
      YANG module version needs to be backward compatible to.</t>
    
      <t>The subscription state change "subscription-started" and
      "subscription-modified" notification messages are also extended to
      include the YANG module revision, version, and YANG library
      content-id. Changes in the revision and version fields
      allow a YANG-Push receiver to detect whenever the subscribed YANG
      module has changed. Changes in the yang-library-content-id that
      YANG module(s) on the network management server of the YANG-Push
      publisher has/have changed.</t>
    
      <section title="Terminology">
        <t>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 <xref target="RFC2119"/> <xref target="RFC8174"/> when,
        and only when, they appear in all capitals, as shown here.</t>
    
        <t>The terms "YANG library" and "YANG library content
        identifier" are used as defined in <xref target="RFC8525"/>.</t>
      </section>	  
    </section>

    <section anchor="Datastore-Selection"
             title="Extend the Datastore Selection">
      <t>The YANG notifications subscription OPTIONALLY can be
      restricted to the following YANG module revision for future
      capabilities:</t>

      <dl>
        <dt>module:</dt>

        <dd>Restricts the subscription to one or more YANG module names
        with revision and version together for the related
        streamed content.</dd>
      </dl>

      <dl>
        <dt>revision:</dt>

        <dd>Restricts the subscription to a specific YANG module
        revision. Example: "2014-05-08".</dd>
      </dl>

      <dl>
        <dt>version:</dt>

        <dd>Restricts the subscription to the latest compatible YANG
        module semantic version referenced to. Example: "2.0.0".</dd>
      </dl>

      <t>When the NETCONF client creates or modifies the subscription
      using the RPCs establish-subscription and modify-subscription and
      the NETCONF server does not support the revision, the
      verson or the combination of revision and version
      specified in the RPC request, the NETCONF server MUST return an
      RPC reply including an &lt;rpc-error&gt; element as defined in
      <xref section="4.3" sectionFormat="of" target="RFC6241"/> with the
      error information populated as follows:</t>

      <ul bare="false" empty="false" spacing="normal">
        <li>an "error-type" node of "application".</li>

        <li>an "error-tag" node whose value is a string that corresponds
        to an identity associated with the error.</li>
      </ul>

      <table align="center" anchor="gen-sub-errors">
        <name slugifiedName="name-general-subscription-error-">General
        Subscription Error Identities and Associated "error-tag" Use
        </name>

        <thead>
          <tr>
            <th align="left" colspan="1" rowspan="1">Error identity</th>

            <th align="left" colspan="1" rowspan="1">
            Uses "error-tag"</th>
          </tr>
        </thead>

        <tbody>
          <tr>
            <td align="left" colspan="1" rowspan="1">
            revision-unsupported</td>

            <td align="left" colspan="1" rowspan="1">
            invalid-value</td>
          </tr>

          <tr>
            <td align="left" colspan="1"
            rowspan="1">version-unsupported</td>

            <td align="left" colspan="1" rowspan="1">invalid-value</td>
          </tr>

          <tr>
            <td align="left" colspan="1"
            rowspan="1">incompatible-revision-and-version</td>

            <td align="left" colspan="1" rowspan="1">invalid-value</td>
          </tr>
        </tbody>
      </table>

      <t><xref target="subscription_establish_sub_example_xml_fig"/>
      provides an example of a "establish-subscription" RPC call with
      YANG revision and datastore-xpath-filter for periodical
      subscription. <xref
target="subscription_establish_sub_positive_response_example_xml_fig"/>
      shows the response when the RPC has been accepted by the NETCONF
      server and <xref
target="subscription_establish_sub_error_response_example_xml_fig"/>
      the error sent by the NETCONF server when the revision is not
      supported.</t>

      <figure anchor="subscription_establish_sub_example_xml_fig"
              title="RPC Example for an establish-subscription">
        <sourcecode type="xml"><![CDATA[
<rpc message-id="101"
    xmlns:netconf="urn:ietf:params:xml:ns:netconf:base:1.0">
  <establish-subscription
      xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications"
      xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-yang-push">
      xmlns:ypr="urn:ietf:params:xml:ns:yang:ietf-yang-push-revision">
    <yp:datastore
        xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
      ds:operational
    </yp:datastore>
    <yp:datastore-xpath-filter
        xmlns:ex="https://example.com/sample-data/1.0">
      /ex:foo
    </yp:datastore-xpath-filter>
    <ypr:module-version>
      <ypr:name>ex:foo</ypr:name>
      <ypr:revision>2023-09-17</ypr:revision>
    </ypr:module-version>
    <yp:periodic>
      <yp:period>500</yp:period>
    </yp:periodic>
  </establish-subscription>
</rpc>
        ]]></sourcecode>
      </figure>

      <figure
anchor="subscription_establish_sub_positive_response_example_xml_fig"
title="RPC Example for a positive establish-subscription response">
        <sourcecode type="xml"><![CDATA[
<rpc-reply message-id="101"
   xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
   <id
     xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications">
      52
   </id>
</rpc-reply>
        ]]></sourcecode>
      </figure>

      <figure
      anchor="subscription_establish_sub_error_response_example_xml_fig"
      title="RPC Example for an error establish-subscription response">
        <sourcecode type="xml"><![CDATA[
<rpc-reply message-id="101"
  xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
  xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications">
  <rpc-error>
    <error-type>application</error-type>
    <error-tag>operation-failed</error-tag>
    <error-severity>error</error-severity>
    <error-path xmlns:ypr="urn:ietf:params:xml:ns:yang:ietf-yang-push-revision">
    <error-info>
      <yp:establish-subscription-error-datastore>
        <yp:reason xmlns:ypr="urn:ietf:params:xml:ns:yang:ietf-yang-push-revision">
          ypr:revision-unsupported
        </yp:reason>
      </yp:establish-subscription-error-datastore>
    </error-info>
  </rpc-error>
</rpc-reply>
        ]]></sourcecode>
      </figure>
    </section>

    <section anchor="Streaming-Update"
             title="Extend the Subscription State Change Notifications">
      <t>Besides the Subscription ID and the xpath or sub-tree filter
      reference as described in <xref section="2.7" sectionFormat="of"
      target="RFC8639"/>, the following metadata objects are part of a 
      "subscription-started" or "subscription-modified" subscription
      state change notification.</t>

      <dl>
        <dt>module:</dt>

        <dd>Describes the YANG module names for the related streamed
        content.</dd>
      </dl>

      <dl>
        <dt>revision:</dt>

        <dd>Describes the YANG module revision as specified in <xref
        section="7.1.9" sectionFormat="of" target="RFC6020"/> for the
        related streamed content.</dd>
      </dl>

      <dl>
        <dt>version:</dt>

        <dd>Describes the YANG module semantic version as specified in
        <xref target="I-D.ietf-netmod-yang-semver"/> for the related
        streamed content.</dd>
      </dl>

      <dl>
        <dt>yang-library-content-id:</dt>

        <dd>Contains the YANG library content identifier <xref
        target="RFC8525"/> which is an implementation-specific
        identifier representing the current information in the YANG
        library on a specific server.</dd>
      </dl>

      <t><xref target="subscription_modified_notif_example_xml_fig"/>
      provides an example of a "subscription-modified" subscription
      state change notification message with the YANG module name,
      revision, version and datastore-xpath-filter for tracking
      the operational status of a single Ethernet interface (per <xref
      target="RFC8343"/>). This subscription state change notification
      message is encoded XML <xref target="W3C.REC-xml-20081126"/> over
      the Network Configuration Protocol (NETCONF) as per <xref
      target="RFC8640"/>.</t>

      <figure anchor="subscription_modified_notif_example_xml_fig"
title="XML Push Example for a subscription-modified notification message">
        <sourcecode type="xml"><![CDATA[
<notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
  <eventTime>2023-01-03T10:00:00Z</eventTime>
  <subscription-modified
      xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications">
    <id>101</id>
    <stream-xpath-filter 
      xmlns:int="urn:ietf:params:xml:ns:yang:ietf-interfaces">
      /int:interfaces
    </stream-xpath-filter>
    <stream>NETCONF</stream>
    <module-version
      xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push-revision">
      <name>ietf-interfaces</name>
      <revision>2018-02-20</revision>
      <version>2.0.0</version>
      <yang-library-content-id>1</yang-library-content-id>
    </module-version>
  </subscription-modified>
</notification>
        ]]></sourcecode>
      </figure>

      <t><xref target="subscription_modified_notif_example_json_fig"/>
      provides an example of a JSON encoded, <xref target="RFC8259"/>,
      subscription state change notification message over HTTPS-based
      <xref target="I-D.ietf-netconf-https-notif"/> or UDP-based <xref
      target="I-D.ietf-netconf-udp-notif"/> transport for the same
      subscription.</t>

      <figure anchor="subscription_modified_notif_example_json_fig"
title="JSON Push Example for a subscription-modified notification message">
        <sourcecode type="json"><![CDATA[
{
  "ietf-restconf:notification" : {
    "eventTime": "2023-01-03T10:00:00Z",
    "ietf-subscribed-notifications:subscription-modified": {
      "id": 101,
      "stream-xpath-filter": "/ietf-interfaces:interfaces",
      "stream": "NETCONF",
      "ietf-yang-push-revision:module-version": [
        {
        "name": "ietf-interfaces"
        "revision": "2018-02-20",
        "version": "2.0.0",
        }
      ],
      "ietf-yang-push-revision:yang-library-content-id": "1",
    }

  }
} 
        ]]></sourcecode>
      </figure>
    </section>

    <section anchor="YANG-push-revision-discovery" title="Discovering
  &quot;ietf-yang-push-revision&quot; Support">
      <t>A client can discover the support of 
      'ietf-yang-push-revision'model through the capabilities model
      defined in <xref target="RFC9196"/>. This documents extends the
      'ietf-notification-capabilities' model with:</t>

      <ul>
        <li>A leaf 'yang-push-module-revision-supported', stating that
        the YANG-Push subscription state change notifications are
        extended with 'revision', 'version' and 
        'yang-library-content-id' extensions.</li>
      </ul>

      <t>The YANG models defined in <xref target="YANG Module"/>
      augments the 'ietf-notification-capabilities' model with the leaf
      listed above.</t>

      <sourcecode type="yangtree"><![CDATA[
module: ietf-system-capabilities
  +--ro system-capabilities
     +--ro datastore-capabilities* [datastore]
     |  +--ro datastore
     |  |       -> /yanglib:yang-library/datastore/name
     |  +--ro per-node-capabilities* []
     |     +--ro (node-selection)?
     |     |  +--:(node-selector)
     |     |     +--ro node-selector?
     |     |             nacm:node-instance-identifier
     |     +--ro notc:subscription-capabilities
     |        +--ro notc:max-nodes-per-update?               uint32
     |        +--ro notc:periodic-notifications-supported?
     |        |       notification-support
     |        +--ro (notc:update-period)?
     |        |  +--:(notc:minimum-update-period)
     |        |  |  +--ro notc:minimum-update-period?        uint32
     |        |  +--:(notc:supported-update-period)
     |        |     +--ro notc:supported-update-period*      uint32
     |        +--ro notc:on-change-supported?
     |        |       notification-support {yp:on-change}?
     |        +--ro notc:minimum-dampening-period?           uint32
     |        |       {yp:on-change}?
     |        +--ro notc:supported-excluded-change-type*     union
     |                {yp:on-change}?
     +--ro notc:subscription-capabilities
        +--ro notc:max-nodes-per-update?                 uint32
        +--ro notc:periodic-notifications-supported?
        |       notification-support
        +--ro (notc:update-period)?
        |  +--:(notc:minimum-update-period)
        |  |  +--ro notc:minimum-update-period?          uint32
        |  +--:(notc:supported-update-period)
        |     +--ro notc:supported-update-period*        uint32
        +--ro notc:on-change-supported?
        |       notification-support {yp:on-change}?
        +--ro notc:minimum-dampening-period?             uint32
        |       {yp:on-change}?
        +--ro notc:supported-excluded-change-type*       union
        |       {yp:on-change}?
        +--ro ypr:yang-push-module-revision-supported?   boolean
       ]]></sourcecode>

      <t>This model can be retrieved via a NETCONF &lt;get&gt; RPC.</t>
    </section>

    <section anchor="YANG-push-revision-module"
             title="The &quot;ietf-yang-push-revision&quot; Module">
      <section anchor="Data Model Overview" title="Data Model Overview">
        <t>This YANG module augments the "ietf-yang-push" module with
        the 'name', 'revision', 'version' and 
        'yang-library-content-id' in the 'subscription-started' and 
        'subscription-modified' subscription state change notifications
        and the ability to define the 'revision' and 'version' in
        the 'establish-subscription' and 'modify-subscription' RPCs in
        the datastore push subscription.</t>

        <section anchor="Tree View" title="Tree View">
          <t>The following is the YANG tree diagram <xref
          target="RFC8340"/> for the 'ietf-yang-push-revision' YANG
          module</t>

          <sourcecode type="yangtree"><![CDATA[
module: ietf-yang-push-revision

  augment /sn:establish-subscription/sn:input:
    +---w module-version-config* [name]
            {yang-push-revision-supported}?
       +---w name        yang:yang-identifier
       +---w revision?   rev:revision-date
       +---w version?    ysver:version
  augment /sn:modify-subscription/sn:input:
    +---w module-version-config* [name]
            {yang-push-revision-supported}?
       +---w name        yang:yang-identifier
       +---w revision?   rev:revision-date
       +---w version?    ysver:version
  augment /sn:subscription-started:
    +--ro module-version* [name] {yang-push-revision-supported}?
    |  +--ro name        yang:yang-identifier
    |  +--ro revision    rev:revision-date
    |  +--ro version?    ysver:version
    +--ro yang-library-content-id?
            -> /yanglib:yang-library/content-id
            {yang-push-revision-supported}?
  augment /sn:subscription-modified:
    +--ro module-version* [name] {yang-push-revision-supported}?
    |  +--ro name        yang:yang-identifier
    |  +--ro revision    rev:revision-date
    |  +--ro version?    ysver:version
    +--ro yang-library-content-id?
            -> /yanglib:yang-library/content-id
            {yang-push-revision-supported}?
  augment /sn:subscriptions/sn:subscription:
    +--rw module-version-config* [name]
            {yang-push-revision-supported}?
       +--rw name        yang:yang-identifier
       +--rw revision?   rev:revision-date
       +--rw version?    ysver:version
  augment /sysc:system-capabilities/notc:subscription-capabilities:
    +--ro yang-push-module-revision-supported?   boolean
]]></sourcecode>
        </section>

        <section anchor="Full Tree View" title="Full Tree View">
          <t>The following is the YANG tree diagram <xref
          target="RFC8340"/> for the 'ietf-yang-push-revision'
          augmentation within the 'ietf-subscribed-notifications',
          including the RPCs and notifications.</t>

          <t><sourcecode type="yangtree"><![CDATA[
module: ietf-yang-push-revision

  augment /sysc:system-capabilities/notc:subscription-capabilities:
    +--ro yang-push-module-revision-supported?   boolean

module: ietf-yang-push

  rpcs:
    +---x resync-subscription {on-change}?
       +---w input
          +---w id    sn:subscription-id

  notifications:
    +---n push-update
    |  +--ro id?                   sn:subscription-id
    |  +--ro datastore-contents?   <anydata>
    |  +--ro incomplete-update?    empty
    +---n push-change-update {on-change}?
       +--ro id?                  sn:subscription-id
       +--ro datastore-changes
       |  +--ro yang-patch
       |     +--ro patch-id    string
       |     +--ro comment?    string
       |     +--ro edit* [edit-id]
       |        +--ro edit-id      string
       |        +--ro operation    enumeration
       |        +--ro target       target-resource-offset
       |        +--ro point?       target-resource-offset
       |        +--ro where?       enumeration
       |        +--ro value?       <anydata>
       +--ro incomplete-update?   empty

module: ietf-subscribed-notifications
  +--ro streams
  |  +--ro stream* [name]
  |     +--ro name                        string
  |     +--ro description?                string
  |     +--ro replay-support?             empty {replay}?
  |     +--ro replay-log-creation-time    yang:date-and-time
  |     |       {replay}?
  |     +--ro replay-log-aged-time?       yang:date-and-time
  |             {replay}?
  +--rw filters
  |  +--rw stream-filter* [name]
  |  |  +--rw name                           string
  |  |  +--rw (filter-spec)?
  |  |     +--:(stream-subtree-filter)
  |  |     |  +--rw stream-subtree-filter?   <anydata> {subtree}?
  |  |     +--:(stream-xpath-filter)
  |  |        +--rw stream-xpath-filter?     yang:xpath1.0 {xpath}?
  |  +--rw yp:selection-filter* [filter-id]
  |     +--rw yp:filter-id                         string
  |     +--rw (yp:filter-spec)?
  |        +--:(yp:datastore-subtree-filter)
  |        |  +--rw yp:datastore-subtree-filter?   <anydata>
  |        |          {sn:subtree}?
  |        +--:(yp:datastore-xpath-filter)
  |           +--rw yp:datastore-xpath-filter?     yang:xpath1.0
  |                   {sn:xpath}?
  +--rw subscriptions
     +--rw subscription* [id]
        +--rw id
        |       subscription-id
        +--rw (target)
        |  +--:(stream)
        |  |  +--rw (stream-filter)?
        |  |  |  +--:(by-reference)
        |  |  |  |  +--rw stream-filter-name
        |  |  |  |          stream-filter-ref
        |  |  |  +--:(within-subscription)
        |  |  |     +--rw (filter-spec)?
        |  |  |        +--:(stream-subtree-filter)
        |  |  |        |  +--rw stream-subtree-filter?
        |  |  |        |          <anydata> {subtree}?
        |  |  |        +--:(stream-xpath-filter)
        |  |  |           +--rw stream-xpath-filter?
        |  |  |                   yang:xpath1.0 {xpath}?
        |  |  +--rw stream
        |  |  |       stream-ref
        |  |  +--ro replay-start-time?
        |  |  |       yang:date-and-time {replay}?
        |  |  +--rw configured-replay?                         empty
        |  |          {configured,replay}?
        |  +--:(yp:datastore)
        |     +--rw yp:datastore
        |     |       identityref
        |     +--rw (yp:selection-filter)?
        |        +--:(yp:by-reference)
        |        |  +--rw yp:selection-filter-ref
        |        |          selection-filter-ref
        |        +--:(yp:within-subscription)
        |           +--rw (yp:filter-spec)?
        |              +--:(yp:datastore-subtree-filter)
        |              |  +--rw yp:datastore-subtree-filter?
        |              |          <anydata> {sn:subtree}?
        |              +--:(yp:datastore-xpath-filter)
        |                 +--rw yp:datastore-xpath-filter?
        |                         yang:xpath1.0 {sn:xpath}?
        +--rw stop-time?
        |       yang:date-and-time
        +--rw dscp?
        |       inet:dscp {dscp}?
        +--rw weighting?                                       uint8
        |       {qos}?
        +--rw dependency?
        |       subscription-id {qos}?
        +--rw transport?
        |       transport {configured}?
        +--rw encoding?
        |       encoding
        +--rw purpose?                                         string
        |       {configured}?
        +--rw (notification-message-origin)? {configured}?
        |  +--:(interface-originated)
        |  |  +--rw source-interface?
        |  |          if:interface-ref {interface-designation}?
        |  +--:(address-originated)
        |     +--rw source-vrf?
        |     |       -> /ni:network-instances/network-instance/name
        |     |       {supports-vrf}?
        |     +--rw source-address?
        |             inet:ip-address-no-zone
        +--ro configured-subscription-state?
        |       enumeration {configured}?
        +--rw receivers
        |  +--rw receiver* [name]
        |     +--rw name                      string
        |     +--ro sent-event-records?
        |     |       yang:zero-based-counter64
        |     +--ro excluded-event-records?
        |     |       yang:zero-based-counter64
        |     +--ro state                     enumeration
        |     +---x reset {configured}?
        |        +--ro output
        |           +--ro time    yang:date-and-time
        +--rw (yp:update-trigger)?
        |  +--:(yp:periodic)
        |  |  +--rw yp:periodic!
        |  |     +--rw yp:period         centiseconds
        |  |     +--rw yp:anchor-time?   yang:date-and-time
        |  +--:(yp:on-change) {on-change}?
        |     +--rw yp:on-change!
        |        +--rw yp:dampening-period?   centiseconds
        |        +--rw yp:sync-on-start?      boolean
        |        +--rw yp:excluded-change*    change-type
        +--rw ypr:module-version-config* [name]
                {yang-push-revision-supported}?
           +--rw ypr:name        yang:yang-identifier
           +--rw ypr:revision?   rev:revision-date
           +--rw ypr:version?    ysver:version

  rpcs:
    +---x establish-subscription
    |  +---w input
    |  |  +---w (target)
    |  |  |  +--:(stream)
    |  |  |  |  +---w (stream-filter)?
    |  |  |  |  |  +--:(by-reference)
    |  |  |  |  |  |  +---w stream-filter-name
    |  |  |  |  |  |          stream-filter-ref
    |  |  |  |  |  +--:(within-subscription)
    |  |  |  |  |     +---w (filter-spec)?
    |  |  |  |  |        +--:(stream-subtree-filter)
    |  |  |  |  |        |  +---w stream-subtree-filter?
    |  |  |  |  |        |          <anydata> {subtree}?
    |  |  |  |  |        +--:(stream-xpath-filter)
    |  |  |  |  |           +---w stream-xpath-filter?
    |  |  |  |  |                   yang:xpath1.0 {xpath}?
    |  |  |  |  +---w stream
    |  |  |  |  |       stream-ref
    |  |  |  |  +---w replay-start-time?
    |  |  |  |          yang:date-and-time {replay}?
    |  |  |  +--:(yp:datastore)
    |  |  |     +---w yp:datastore
    |  |  |     |       identityref
    |  |  |     +---w (yp:selection-filter)?
    |  |  |        +--:(yp:by-reference)
    |  |  |        |  +---w yp:selection-filter-ref
    |  |  |        |          selection-filter-ref
    |  |  |        +--:(yp:within-subscription)
    |  |  |           +---w (yp:filter-spec)?
    |  |  |              +--:(yp:datastore-subtree-filter)
    |  |  |              |  +---w yp:datastore-subtree-filter?
    |  |  |              |          <anydata> {sn:subtree}?
    |  |  |              +--:(yp:datastore-xpath-filter)
    |  |  |                 +---w yp:datastore-xpath-filter?
    |  |  |                         yang:xpath1.0 {sn:xpath}?
    |  |  +---w stop-time?
    |  |  |       yang:date-and-time
    |  |  +---w dscp?
    |  |  |       inet:dscp {dscp}?
    |  |  +---w weighting?
    |  |  |       uint8 {qos}?
    |  |  +---w dependency?
    |  |  |       subscription-id {qos}?
    |  |  +---w encoding?
    |  |  |       encoding
    |  |  +---w (yp:update-trigger)?
    |  |  |  +--:(yp:periodic)
    |  |  |  |  +---w yp:periodic!
    |  |  |  |     +---w yp:period         centiseconds
    |  |  |  |     +---w yp:anchor-time?   yang:date-and-time
    |  |  |  +--:(yp:on-change) {on-change}?
    |  |  |     +---w yp:on-change!
    |  |  |        +---w yp:dampening-period?   centiseconds
    |  |  |        +---w yp:sync-on-start?      boolean
    |  |  |        +---w yp:excluded-change*    change-type
    |  |  +---w ypr:module-version-config* [name]
    |  |          {yang-push-revision-supported}?
    |  |     +---w ypr:name        yang:yang-identifier
    |  |     +---w ypr:revision?   rev:revision-date
    |  |     +---w ypr:version?    ysver:version
    |  +--ro output
    |     +--ro id                            subscription-id
    |     +--ro replay-start-time-revision?   yang:date-and-time
    |             {replay}?
    +---x modify-subscription
    |  +---w input
    |     +---w id
    |     |       subscription-id
    |     +---w (target)
    |     |  +--:(stream)
    |     |  |  +---w (stream-filter)?
    |     |  |     +--:(by-reference)
    |     |  |     |  +---w stream-filter-name
    |     |  |     |          stream-filter-ref
    |     |  |     +--:(within-subscription)
    |     |  |        +---w (filter-spec)?
    |     |  |           +--:(stream-subtree-filter)
    |     |  |           |  +---w stream-subtree-filter?
    |     |  |           |          <anydata> {subtree}?
    |     |  |           +--:(stream-xpath-filter)
    |     |  |              +---w stream-xpath-filter?
    |     |  |                      yang:xpath1.0 {xpath}?
    |     |  +--:(yp:datastore)
    |     |     +---w yp:datastore
    |     |     |       identityref
    |     |     +---w (yp:selection-filter)?
    |     |        +--:(yp:by-reference)
    |     |        |  +---w yp:selection-filter-ref
    |     |        |          selection-filter-ref
    |     |        +--:(yp:within-subscription)
    |     |           +---w (yp:filter-spec)?
    |     |              +--:(yp:datastore-subtree-filter)
    |     |              |  +---w yp:datastore-subtree-filter?
    |     |              |          <anydata> {sn:subtree}?
    |     |              +--:(yp:datastore-xpath-filter)
    |     |                 +---w yp:datastore-xpath-filter?
    |     |                         yang:xpath1.0 {sn:xpath}?
    |     +---w stop-time?
    |     |       yang:date-and-time
    |     +---w (yp:update-trigger)?
    |     |  +--:(yp:periodic)
    |     |  |  +---w yp:periodic!
    |     |  |     +---w yp:period         centiseconds
    |     |  |     +---w yp:anchor-time?   yang:date-and-time
    |     |  +--:(yp:on-change) {on-change}?
    |     |     +---w yp:on-change!
    |     |        +---w yp:dampening-period?   centiseconds
    |     +---w ypr:module-version-config* [name]
    |             {yang-push-revision-supported}?
    |        +---w ypr:name        yang:yang-identifier
    |        +---w ypr:revision?   rev:revision-date
    |        +---w ypr:version?    ysver:version
    +---x delete-subscription
    |  +---w input
    |     +---w id    subscription-id
    +---x kill-subscription
       +---w input
          +---w id    subscription-id

  notifications:
    +---n replay-completed {replay}?
    |  +--ro id    subscription-id
    +---n subscription-completed {configured}?
    |  +--ro id    subscription-id
    +---n subscription-modified
    |  +--ro id
    |  |       subscription-id
    |  +--ro (target)
    |  |  +--:(stream)
    |  |  |  +--ro (stream-filter)?
    |  |  |  |  +--:(by-reference)
    |  |  |  |  |  +--ro stream-filter-name
    |  |  |  |  |          stream-filter-ref
    |  |  |  |  +--:(within-subscription)
    |  |  |  |     +--ro (filter-spec)?
    |  |  |  |        +--:(stream-subtree-filter)
    |  |  |  |        |  +--ro stream-subtree-filter?
    |  |  |  |        |          <anydata> {subtree}?
    |  |  |  |        +--:(stream-xpath-filter)
    |  |  |  |           +--ro stream-xpath-filter?
    |  |  |  |                   yang:xpath1.0 {xpath}?
    |  |  |  +--ro stream
    |  |  |  |       stream-ref
    |  |  |  +--ro replay-start-time?
    |  |  |          yang:date-and-time {replay}?
    |  |  +--:(yp:datastore)
    |  |     +--ro yp:datastore
    |  |     |       identityref
    |  |     +--ro (yp:selection-filter)?
    |  |        +--:(yp:by-reference)
    |  |        |  +--ro yp:selection-filter-ref
    |  |        |          selection-filter-ref
    |  |        +--:(yp:within-subscription)
    |  |           +--ro (yp:filter-spec)?
    |  |              +--:(yp:datastore-subtree-filter)
    |  |              |  +--ro yp:datastore-subtree-filter?
    |  |              |          <anydata> {sn:subtree}?
    |  |              +--:(yp:datastore-xpath-filter)
    |  |                 +--ro yp:datastore-xpath-filter?
    |  |                         yang:xpath1.0 {sn:xpath}?
    |  +--ro stop-time?
    |  |       yang:date-and-time
    |  +--ro dscp?
    |  |       inet:dscp {dscp}?
    |  +--ro weighting?                                       uint8
    |  |       {qos}?
    |  +--ro dependency?
    |  |       subscription-id {qos}?
    |  +--ro transport?
    |  |       transport {configured}?
    |  +--ro encoding?
    |  |       encoding
    |  +--ro purpose?                                         string
    |  |       {configured}?
    |  +--ro (yp:update-trigger)?
    |  |  +--:(yp:periodic)
    |  |  |  +--ro yp:periodic!
    |  |  |     +--ro yp:period         centiseconds
    |  |  |     +--ro yp:anchor-time?   yang:date-and-time
    |  |  +--:(yp:on-change) {on-change}?
    |  |     +--ro yp:on-change!
    |  |        +--ro yp:dampening-period?   centiseconds
    |  |        +--ro yp:sync-on-start?      boolean
    |  |        +--ro yp:excluded-change*    change-type
    |  +--ro ypr:module-version* [name]
    |  |       {yang-push-revision-supported}?
    |  |  +--ro ypr:name        yang:yang-identifier
    |  |  +--ro ypr:revision    rev:revision-date
    |  |  +--ro ypr:version?    ysver:version
    |  +--ro ypr:yang-library-content-id?
    |          -> /yanglib:yang-library/content-id
    |          {yang-push-revision-supported}?
    +---n subscription-resumed
    |  +--ro id    subscription-id
    +---n subscription-started {configured}?
    |  +--ro id
    |  |       subscription-id
    |  +--ro (target)
    |  |  +--:(stream)
    |  |  |  +--ro (stream-filter)?
    |  |  |  |  +--:(by-reference)
    |  |  |  |  |  +--ro stream-filter-name
    |  |  |  |  |          stream-filter-ref
    |  |  |  |  +--:(within-subscription)
    |  |  |  |     +--ro (filter-spec)?
    |  |  |  |        +--:(stream-subtree-filter)
    |  |  |  |        |  +--ro stream-subtree-filter?
    |  |  |  |        |          <anydata> {subtree}?
    |  |  |  |        +--:(stream-xpath-filter)
    |  |  |  |           +--ro stream-xpath-filter?
    |  |  |  |                   yang:xpath1.0 {xpath}?
    |  |  |  +--ro stream
    |  |  |  |       stream-ref
    |  |  |  +--ro replay-start-time?
    |  |  |  |       yang:date-and-time {replay}?
    |  |  |  +--ro replay-previous-event-time?
    |  |  |          yang:date-and-time {replay}?
    |  |  +--:(yp:datastore)
    |  |     +--ro yp:datastore
    |  |     |       identityref
    |  |     +--ro (yp:selection-filter)?
    |  |        +--:(yp:by-reference)
    |  |        |  +--ro yp:selection-filter-ref
    |  |        |          selection-filter-ref
    |  |        +--:(yp:within-subscription)
    |  |           +--ro (yp:filter-spec)?
    |  |              +--:(yp:datastore-subtree-filter)
    |  |              |  +--ro yp:datastore-subtree-filter?
    |  |              |          <anydata> {sn:subtree}?
    |  |              +--:(yp:datastore-xpath-filter)
    |  |                 +--ro yp:datastore-xpath-filter?
    |  |                         yang:xpath1.0 {sn:xpath}?
    |  +--ro stop-time?
    |  |       yang:date-and-time
    |  +--ro dscp?
    |  |       inet:dscp {dscp}?
    |  +--ro weighting?                                       uint8
    |  |       {qos}?
    |  +--ro dependency?
    |  |       subscription-id {qos}?
    |  +--ro transport?
    |  |       transport {configured}?
    |  +--ro encoding?
    |  |       encoding
    |  +--ro purpose?                                         string
    |  |       {configured}?
    |  +--ro (yp:update-trigger)?
    |  |  +--:(yp:periodic)
    |  |  |  +--ro yp:periodic!
    |  |  |     +--ro yp:period         centiseconds
    |  |  |     +--ro yp:anchor-time?   yang:date-and-time
    |  |  +--:(yp:on-change) {on-change}?
    |  |     +--ro yp:on-change!
    |  |        +--ro yp:dampening-period?   centiseconds
    |  |        +--ro yp:sync-on-start?      boolean
    |  |        +--ro yp:excluded-change*    change-type
    |  +--ro ypr:module-version* [name]
    |  |       {yang-push-revision-supported}?
    |  |  +--ro ypr:name        yang:yang-identifier
    |  |  +--ro ypr:revision    rev:revision-date
    |  |  +--ro ypr:version?    ysver:version
    |  +--ro ypr:yang-library-content-id?
    |          -> /yanglib:yang-library/content-id
    |          {yang-push-revision-supported}?
    +---n subscription-suspended
    |  +--ro id        subscription-id
    |  +--ro reason    identityref
    +---n subscription-terminated
       +--ro id        subscription-id
       +--ro reason    identityref
]]></sourcecode></t>
        </section>
      </section>

      <section anchor="YANG Module" title="YANG Module">
        <t>The YANG module has two leaves augmenting the model of <xref
        target="RFC8639">Subscription to YANG Notifications</xref>.</t>

        <sourcecode type="yang" markers="true"
        name="ietf-yang-push-revision@2025-08-29.yang"><![CDATA[
module ietf-yang-push-revision {
  yang-version 1.1;
  namespace
    "urn:ietf:params:xml:ns:yang:ietf-yang-push-revision";
  prefix ypr;
  import ietf-subscribed-notifications {
    prefix sn;
    reference
      "RFC 8639: Subscription to YANG Notifications";
  }
  import ietf-yang-revisions {
    prefix rev;
    reference
      "RFC YYYY: draft-ietf-netmod-yang-module-versioning-13,
      Updated YANG Module Revision Handling";
  }
  import ietf-yang-types {
    prefix yang;
    rev:recommended-min-date "2013-07-15";
    reference
      "RFC 6991: Common YANG Data Types.";
  }
  import ietf-yang-semver {
    prefix ysver;
    reference
      "RFC ZZZZ: draft-ietf-netmod-yang-semver-23, YANG Semantic
      Versioning";
  }
  import ietf-yang-library {
    prefix yanglib;
    reference
      "RFC 8525: YANG Library";
  }
  import ietf-system-capabilities {
    prefix sysc;
    reference
      "RFC 9196: YANG Modules Describing Capabilities for
       Systems and Datastore Update Notifications";
  }
  import ietf-notification-capabilities {
    prefix notc;
    reference
      "RFC 9196: YANG Modules Describing Capabilities for
       Systems and Datastore Update Notifications";
  }

  organization "IETF NETCONF (Network Configuration) Working Group";
  contact
    "WG Web:   <http:/tools.ietf.org/wg/netconf/>
     WG List:  <mailto:netconf@ietf.org>

     Authors:  Thomas Graf
               <mailto:thomas.graf@swisscom.com>
               Benoit Claise
               <mailto:benoit.claise@huawei.com>
               Alex Huang Feng
               <mailto:alex.huang-feng@insa-lyon.fr>";

  description
    "Defines YANG-Push event notification header with the revision
    and the version. Adds the support of the revision and
    version selection in the YANG-Push subscription RPCs.

    Copyright (c) 2025 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 Revised 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).

    All revisions of IETF and IANA published modules can be found
    at the YANG Parameters registry
    (https://www.iana.org/assignments/yang-parameters).

    This version of this YANG module is part of RFC XXXX; 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.";

  revision 2025-08-29 {
    description
      "First revision";
    reference
      "RFC XXXX: Support of Versioning in YANG Notifications
      Subscription";
  }

  feature yang-push-revision-supported {
    description
      "This feature indicates the YANG Subscription Notifications
      supports specifying the list of modules, revisions and
      version in the YANG subscription.";
  }

  // Identities
  identity revision-unsupported {
    base sn:establish-subscription-error;
    base sn:modify-subscription-error;
    description
      "Revision not supported.  This failure can be due to
      subscribing to a specific revision not supported by the
      publisher.";
  }

  identity version-unsupported {
    base sn:establish-subscription-error;
    base sn:modify-subscription-error;
    description
      "Version not supported.  This failure can be due to 
      subscribing to a specific version not supported by the
      publisher.";
  }

  identity incompatible-revision-and-version {
    base sn:establish-subscription-error;
    base sn:modify-subscription-error;
    description
      "The combination of revision and the version are
      incompatible. This failure happens when the revision and the
      version are both specified in the RPC and the YANG
      module supported by the publisher does not support one of the
      revision or the version.";
  }

  grouping yang-push-module-version-config {
    description
      "This grouping combines the module name, the revision and
      version leaves. This grouping is to be used for
      configuration and the leaves are not mandatory.";
    leaf name {
      type yang:yang-identifier;
      description
        "This references the YANG module name.";
    }
    leaf revision {
      type rev:revision-date;
      description
        "This references the YANG module revision to be sent in the
        subscription.";
    }
    leaf version {
      type ysver:version;
      description
        "This references the YANG module semantic version to be sent
        in the subscription.";
    }
  }

  grouping yang-push-module-version {
    description
      "This grouping combines the module name, the revision and
      version leaves. This grouping is to be used for
      read-only cases such as the content of YANG-Push Notifications.
      The name and revision are mandatory and MUST be present
      in the data.";
    leaf name {
      type yang:yang-identifier;
      config false;
      mandatory true;
      description
        "This references the YANG module name.";
    }
    leaf revision {
      type rev:revision-date;
      config false;
      mandatory true;
      description
        "This references the YANG module revision of the sent
        notification message.";
    }
    leaf version {
      type ysver:version;
      description
        "This references the YANG module semantic version of the
        sent notification message.";
    }
  }

  grouping yang-push-module-version-list {
    description
      "This grouping defines a list of yang-push-module-version
      grouping.";
    list module-version {
      key "name";
      config false;
      description
        "List of yang-push-module-version grouping. The revision is
        not configurable.";
      uses ypr:yang-push-module-version;
    }
    leaf yang-library-content-id {
      type leafref {
        path "/yanglib:yang-library/yanglib:content-id";
      }
      config false;
      description
        "Contains the YANG library content identifier RFC 8525
        information.";
    }
  }

  grouping yang-push-module-version-config-list {
    description
      "This grouping defines a list of yang-push-module-version-config
      grouping.";
    list module-version-config {
      key "name";
      description
        "List of yang-push-module-version-config grouping. The
        revision is configurable.";
      uses ypr:yang-push-module-version-config;
    }
  }

  // Subscription parameters
  augment "/sn:establish-subscription/sn:input" {
    if-feature "yang-push-revision-supported";
    description
      "Augment the establish-subscription RPC from the
      ietf-subscribed-notifications YANG module with the
      yang-push-module-version-config-list grouping.";
    uses ypr:yang-push-module-version-config-list;
  }
  augment "/sn:modify-subscription/sn:input" {
    if-feature "yang-push-revision-supported";
    description
      "Augment the modify-subscription RPC from the
      ietf-subscribed-notifications YANG module with the
      yang-push-module-version-config-list grouping.";
    uses ypr:yang-push-module-version-config-list;
  }

  // Subscription notifications
  augment "/sn:subscription-started" {
    if-feature "yang-push-revision-supported";
    description
      "Augment the subscription-started notification from the
      ietf-subscribed-notifications YANG module with the
      yang-push-module-version-list grouping.";
    uses ypr:yang-push-module-version-list;
  }
  augment "/sn:subscription-modified" {
    if-feature "yang-push-revision-supported";
    description
      "Augment the subscription-modified notification from the
      ietf-subscribed-notifications YANG module with the
      yang-push-module-version-list grouping.";
    uses ypr:yang-push-module-version-list;
  }

  // Subscription container
  augment "/sn:subscriptions/sn:subscription" {
    if-feature "yang-push-revision-supported";
    description
      "Augment the subscriptions RPC container from the
      ietf-subscribed-notifications YANG module with the
      yang-push-module-version-config-list grouping.";
    uses ypr:yang-push-module-version-config-list;
  }

  // Event capabilities
  augment "/sysc:system-capabilities/notc:subscription-capabilities" {
    description
      "Add system level capabilities";
    leaf yang-push-module-revision-supported {
      type boolean;
      description
        "Specifies whether the publisher supports exporting
        revision and version in YANG-Push subscription state change
        notifications.";
      reference
        "RFC XXXX: Support of Versioning in YANG Notifications
        Subscription";
    }
  }
}
]]></sourcecode>
      </section>
    </section>

    <section anchor="IANA_Considerations" title="IANA Considerations">
      <section title="IETF XML Registry">
        <t>This document registers the following URIs in the "IETF XML
        Registry" <xref target="RFC3688"/>:</t>

        <t><figure>
            <artwork align="left"><![CDATA[
  URI: urn:ietf:params:xml:ns:yang:ietf-yang-push-revision
  Registrant Contact: The IESG.
  XML: N/A; the requested URI is an XML namespace.]]></artwork>
          </figure></t>
      </section>

      <section title="YANG Module Name">
        <t>This document registers the following YANG modules in the 
        'YANG Module Names' registry <xref target="RFC6020"/>:</t>

        <t><figure>
            <artwork align="left"><![CDATA[
  name: ietf-yang-push-revision
  namespace: urn:ietf:params:xml:ns:yang:ietf-yang-push-revision
  prefix: ypr
  reference: RFC-to-be]]></artwork>
          </figure></t>
      </section>
    </section>

    <section anchor="Operational" title="Operational Considerations">
      <t>A YANG package <xref target="I-D.ietf-netmod-yang-packages"/>,
      specifies a versioned organizational structure used to manage a
      set of YANG modules that collectively defines a package schema.
      For example, a YANG package could contain a set of YANG modules
      required to implement a L3VPN service on a network node. It offers
      therefore a complementary information to the solution in this
      draft by describing how one specifi YANG module revision is part
      of a set of YANG modules.</t>
    </section>

    <section anchor="Implementation" title="Implementation Status">
      <t>Note to the RFC-Editor: Please remove this section before
      publishing.</t>

      <section anchor="Huawei" title="Huawei VRP">
        <t>Huawei implemented in notification the 'module', 'revision'
        and 'version' extension as described in  <xref
        target="Streaming-Update"/> for a YANG-Push publisher on <xref
        target="I-D.ietf-netconf-udp-notif">UDP-based Transport for
        Configured Subscriptions</xref> in their VRP platform.</t>
      </section>

      <section anchor="SIXWIND" title="6WIND VSR">
        <t>6WIND implemented in notification 'module', 'revision' 
        and 'library-content-id' extension as described in <xref
        target="Streaming-Update"/> for a YANG-Push publisher on <xref
        target="I-D.ietf-netconf-udp-notif">UDP-based Transport for
        Configured Subscriptions</xref> in their VSR platform.</t>
      </section>

      <section anchor="Cisco" title="Cisco IOS XR">
        <t>Cisco implemented in notification 'module', 'revision' and 
        'library-content-id' extension as described in <xref
        target="Streaming-Update"/> and 'module' and 'revision' in 
        subscription as described in <xref
        target="Datastore-Selection"/> for a YANG-Push publisher on
        <xref target="I-D.ietf-netconf-udp-notif">UDP-based Transport
        for Configured Subscriptions</xref> in their IOS XR platform.
        </t>
      </section>
    </section>

    <section anchor="Security" title="Security Considerations">
      <t>The security considerations for the YANG notifications
      subscription mechanism are described in <xref target="RFC8641"/>.
      This documents adds no additional security considerations.</t>
    </section>

    <section anchor="Acknowledgements" title="Acknowledgements">
      <t>The authors would like to thank Qiufang Ma, Robert Wilton and
      Jian Ping Zhang for their review and valuable comments.</t>
    </section>
  </middle>

  <back>
    <references title="Normative References">
      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.3688.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6020.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6241.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8525.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8639.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8641.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9196.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml-ids/reference.I-D.ietf-netmod-yang-module-versioning.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml-ids/reference.I-D.ietf-netmod-yang-semver.xml'?>
    </references>

    <references title="Informative References">
      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8259.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8340.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8343.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8640.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml-ids/reference.I-D.ietf-netconf-https-notif.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml-ids/reference.I-D.ietf-netconf-udp-notif.xml'?>

      <?rfc include='https://bib.ietf.org/public/rfc/bibxml-ids/reference.I-D.ietf-netmod-yang-packages.xml'?>

      <reference anchor="W3C.REC-xml-20081126"
                 derivedAnchor="W3C.REC-xml-20081126" quoteTitle="true"
                 target="https://www.w3.org/TR/2008/REC-xml-20081126">
        <front>
          <title>Extensible Markup Language (XML) 1.0 (Fifth Edition)</title>

          <author fullname="Tim Bray" initials="T." surname="Bray">
            <organization showOnFrontPage="true"/>
          </author>

          <author fullname="Jean Paoli" initials="J." surname="Paoli">
            <organization showOnFrontPage="true"/>
          </author>

          <author fullname="Michael Sperberg-McQueen" initials="M."
                  surname="Sperberg-McQueen">
            <organization showOnFrontPage="true"/>
          </author>

          <author fullname="Eve Maler" initials="E." surname="Maler">
            <organization showOnFrontPage="true"/>
          </author>

          <author fullname="Francois Yergeau" initials="F." surname="Yergeau">
            <organization showOnFrontPage="true"/>
          </author>

          <date month="November" year="2008"/>
        </front>

        <refcontent>World Wide Web Consortium Recommendation
        REC-xml-20081126</refcontent>
      </reference>
    </references>
  </back>
</rfc>
