This is an ops-dir review of draft-ietf-appsawg-xml-mediatypes-09. According to the introduction, this document replaces RFC 3023 and revamps the IETF XML-related IANA registries, redefines the areas of alignment between some XML datatypes and the addition of a new identifier and base URI. It also makes some other backwards-incompatible changes. As a document that defines data types and the like I do not see any operational issues per se but the backwards-incompatible changes could present an operational issue. I think the document could benefit from pulling the various notes about incompatibilities, changes and operational issues (such as the last paragraph of appendix C) that are currently in the document into a single operational considerations section or appendix. Scott