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 primarily for the benefit of the operational area directors. Document editors and WG chairs should treat these comments just like any other last call comments. Summary: Ready This document describes a modification to the base ABNF definition to allow the specification of case-sensitive string literals. This may impact those developing protocol specifications and those implementing IETF protocol specifications but is not likely to have an operational impact. It is possible (but not likely) that there may be future impacts on existing OAM protocols in -bis specifications. Any nits we noticed were picked up in the sec-dir review ( https://www.ietf.org/mail-archive/web/secdir/current/msg05000.html ). Melinda