Add IANA information

yang-module-versioning/draft-ietf-netmod-yang-module-versioning.xml

@@ -1074,9 +1074,59 @@ module ietf-yang-library-revisions {
     <t>Reference: [RFCXXXX]</t>
   </list></t>
   </section>
-  <section title="Instructions">
-    <t>We may need to give new instructions to IANA e.g. how to review revision-label
-      statements to make sure they are accurate? TBD</t>
+  <section title="Guidance for versioning in IANA maintained YANG modules">
+    <t>Note for IANA (to be removed by the RFC editor): Please check that the
+    registries and IANA YANG modules are referenced in the appropriate way.</t>
+
+    <t>IANA is responsible for maintaining and versioning YANG modules that are
+    derived from other IANA registries. For example, <xref
+    target="IfTypeYang">"iana-if-type.yang"</xref> is derived from the <xref
+    target="IfTypesReg">"Interface Types (ifType) IANA registry"</xref>, and <xref
+    target="RoutingTypesYang">"iana-routing-types.yang"</xref> is derived from
+    the <xref target="AddrFamilyReg">"Address Family Numbers"</xref> and <xref
+    target="SAFIReg">"Subsequent Address Family Identifiers (SAFI)
+    Parameters"</xref> IANA registries.</t>
+
+    <t>Normally, updates to the registries cause any derived YANG modules to be
+    updated in a backwards-compatible way, but there are some cases where the
+    registry updates can cause non-backward-compatible updates to the derived
+    YANG module.  An example of such an update is the 2020-12-31 revision of
+    iana-routing-types.yang <xref target="RoutingTypesDecRevision"/>, where the
+    enum name for two SAFI values was changed.</t>
+
+    <t>In all cases, IANA MUST follow the versioning guidance specified in <xref
+    target="update_rules"/>, and MUST include a "rev:nbc-changes" substatement
+    to the latest revision statement whenever an IANA maintained module is
+    updated in a non-backwards-compatible way, as described in <xref
+    target="nbc_marker"/>.</t>
+
+    <t>Note: For published IANA maintained YANG modules that contain
+    non-backwards-compatible changes between revisions, a new revision should be
+    published with the "rev:nbc-changes" substatement retrospectively added to
+    any revisions containing non-backwards-compatible changes.</t>
+
+    <t>Non normative examples of updates to enumeration types in IANA maintained
+    modules that would be classified as non-backwards-compatible changes are:
+    Changing the status of an enumeration typedef to obsolete, changing the
+    status of an enum entry to obsolete, removing an enum entry, changing the
+    identifier of an enum entry, or changing the described meaning of an enum
+    entry.</t>
+
+    <t>Non normative examples of updates to enumeration types in IANA maintained
+    modules that would be classified as backwards-compatible changes are: Adding
+    a new enum entry to the end of the enumeration, changing the status or an
+    enum entry to deprecated, or improving the description of an enumeration that
+    does not change its defined meaning.</t>
+
+    <t>Non normative examples of updates to identity types in IANA maintained
+    modules that would be classified as non-backwards-compatible changes are:
+    Changing the status of an identity to obsolete, removing an identity,
+    renaming an identity, or changing the described meaning of an identity.</t>
+
+    <t>Non normative examples of updates to identity types in IANA maintained
+    modules that would be classified as backwards-compatible changes are: Adding
+    a new identity, changing the status or an identity to deprecated, or improving
+    the description of an identity that does not change its defined meaning.</t>
   </section>
 </section>
 </middle>
@@ -1102,11 +1152,53 @@ module ietf-yang-library-revisions {
    <?ref include='reference.I-D.ietf-netmod-yang-versioning-reqs'?>
    <reference anchor="semver" target="https://www.semver.org">
       <front>
-       <title>Semantic Versioning 2.0.0</title>
-       <author/>
-       <date/>
-    </front>
-  </reference>
+        <title>Semantic Versioning 2.0.0</title>
+        <author/>
+        <date/>
+      </front>
+   </reference>
+   <reference anchor="IfTypesReg" target="https://www.iana.org/assignments/smi-numbers/smi-numbers.xhtml#smi-numbers-5">
+      <front>
+        <title>Interface Types (ifType) IANA Registry</title>
+        <author/>
+        <date/>
+      </front>
+   </reference>
+   <reference anchor="IfTypeYang" target="https://www.iana.org/assignments/iana-if-type/iana-if-type.xhtml">
+      <front>
+        <title>iana-if-type YANG Module</title>
+        <author/>
+        <date/>
+      </front>
+   </reference>
+   <reference anchor="AddrFamilyReg" target="https://www.iana.org/assignments/address-family-numbers/address-family-numbers.xhtml">
+      <front>
+        <title>Address Family Numbers IANA Registry</title>
+        <author/>
+        <date/>
+      </front>
+   </reference>
+   <reference anchor="SAFIReg" target="https://www.iana.org/assignments/safi-namespace/safi-namespace.xhtml">
+      <front>
+        <title>Subsequent Address Family Identifiers (SAFI) Parameters IANA Registry</title>
+        <author/>
+        <date/>
+      </front>
+   </reference>
+   <reference anchor="RoutingTypesYang" target="https://www.iana.org/assignments/iana-routing-types/iana-routing-types.xhtml">
+      <front>
+        <title>iana-routing-types YANG Module</title>
+        <author/>
+        <date/>
+      </front>
+   </reference>
+   <reference anchor="RoutingTypesDecRevision" target="https://www.iana.org/assignments/yang-parameters/iana-routing-types@2020-12-31.yang">
+      <front>
+        <title>2020-12-31 revision of iana-routing-types.yang</title>
+        <author/>
+        <date/>
+      </front>
+   </reference>
 </references>
 <?rfc needLines="100"?>