Hi, 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 primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments. The summary of the review is Ready with Issues. The Security Considerations section doesn't give any guidance regarding errors, boundaries, or limits. For example, the specification requires that certain fields MUST be set to 0, but no guidance is given of what a receiver is to do if it receives a packet with that field not set to 0. Similarly, the specification requires that a list of IOAM Namespace-IDs be transmitted. What should a receiver do if the list includes duplicate entries, or if it receives a Namespace-ID that is not defined? Please add some bounds checking and limits in the Security Considerations section. The specification frequently references RFC 9197, which appears to have a well-developed Security Considerations section. It would be appropriate if the Security Considerations section of this ID were to reference that Security Considerations section and require that implementations of this specification follow the guidance given there. Other than those issues, I found the document to be understandable and well written. I found no nits. Regards, Chris