I have reviewed this document as part of the Operational directorate’s ongoing effort to review all IETF documents being processed by the IESG.  These comments were written with the intent of improving the operational aspects of the IETF drafts. Comments that are 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: The document provides updates to RFC 5280 providing clarity on the handling of Internationalized Domain Names (IDNs) and Internationalized Email Addresses in X.509 Certificates. Comments: The document provides clarifications on the handling of Internationalized Domain Names (IDNs) and Internationalized Email Addresses in X.509 Certificates. As such it has no operational or management impact.