Hi, this is my YANG Doctor review of draft-ietf-bfd-optimizing-authentication, the requested revision is 16, but it is currently at version 18, so my review is based on the latest.

This draft defines a YANG module which augments the base BFD YANG model in RFC 9314, and also has an IANA-maintained module in Appendix which updates the initial one in RFC 9127. Both YANG modules have been parsed by yanglint and pyang, which didn’t generate any warnings and errors.

Some nits that need to be fixed:
1.	Sec.5.1 states “Finally, it adds a flag to enable optimized authentication, an interval value that specifies how often the BFD session should be re-authenticated once it is in the Up state, and the key chain that should be used in the Up state.”
But I think the YANG module only defines the reauth-interval, which is inconsistent with the narrative description.

2.	The YANG module in sec.5.3 imports a set of modules from RFC 9314, but the reference statement to RFC 9314 should be:
OLD:   
    reference
      "RFC 9314: YANG Data Model for Bidirectional
       Forwarding Detection.";
NEW:
    reference
      "RFC 9314: YANG Data Model for Bidirectional
       Forwarding Detection (BFD)”;

3.	The YANG module in sec.5.3, reference statement to RFC 8177 should be:
OLD:
    reference
      "RFC 8177: YANG Key Chain.";
NEW:
    reference
      " RFC 8177: YANG Data Model for Key Chains";

4.	The YANG module in sec.5.3, please update the reference for identity definitions optimized-md5-meticulous-keyed-isaac and optimized-sha1-meticulous-keyed-isaac as follows:
OLD:
    reference
      "I-D.ietf-bfd-optimizing-authentication:
         Meticulous Keyed ISAAC for BFD Authentication.
       I-D.ietf-bfd-secure-sequence-numbers:
         Meticulous Keyed ISAAC for BFD Authentication.";
NEW:
     reference
        "RFC XXXX: Optimizing BFD Authentication
         RFC YYYY: Meticulous Keyed ISAAC for BFD Authentication";
And also add a note to RFC editor that YYYY is the number assigned to I-D.ietf-bfd-secure-sequence-numbers at the time of publication.

5.	The YANG module in sec.5.3, the description for all the augment substatements are identical, distinction should be made here between the descriptions of different modules being augmented.

6.	Sec.6.4 requests an update to the IANA-maintained YANG module “iana-bfd-types.yang”, maybe it should also mention the revision of this YANG module is to mirror the update to the registry “BFD Authentication Types” as requested in sec.6.1.

7.	Appendix A, the description:
OLD:  
  This version of this YANG module is part of RFC 9127; see the
  RFC itself for full legal notices.
NEW:
  The initial version of this YANG module is part of RFC 9127; see the
  RFC itself for full legal notices.
  (and I think the reference below should be RFC XXXX instead of RFC 9127)

8.	Appendix A, the reference:
OLD:
    reference
      "I-D.ietf-bfd-optimizing-authentication:
           Optimizing BFD Authentication,
       I-D.ietf-bfd-stability: BFD Stability.";
NEW:
    reference
      "RFC XXXX: Optimizing BFD Authentication
       RFC ZZZZ: BFD Stability";
And also add a note to RFC editor that ZZZZ is the number assigned to I-D.ietf-bfd-stability at the time of publication.

9.	RFC 8340 should be informative reference rather than normative one. 
See section 3.4 in https://datatracker.ietf.org/doc/draft-ietf-netmod-rfc8407bis/: 
“If YANG tree diagrams are used, then an informative reference to the YANG tree diagrams specification MUST be included in the document."