I have reviewed this document as part of the security directorate's
ongoing effort to review all IETF documents being processed by the
IESG.  These comments were written with the intent of improving
security requirements and considerations in IETF drafts.  Comments
not addressed in last call may be included in AD reviews during the
IESG review.  Document editors and WG chairs should treat these
comments just like any other last call comments.

Summary: Ready

I have reviewed version 5 of draft-ietf-core-target-attr. This draft defines the registry of target attributes for CoRE links. As stated in the Security Sections, the registry itself does not introduce new security issues. Those should be analyzed as part of the web linking specification (RFC 8288), the link format for CoRE (RFC 6990), CoAP (RFC 7252), the CoRE resource directory (RFC 9176), or the specifications of newly defined attributes.

The draft does not propose to use the registry as a control point before new target attributes can be used, which is probably realistic as new target attributes could be introduced outside of the IETF purview. The registry is then just used to register these attributes, in order to avoid name collisions. I suppose that the registration phase would provide an opportunity to document security or privacy issues associated with new target attributes, and that any such issues would be outlined in the expert review. Hopefully.