We have reviewed the CURIE draft and discussed it at our F2F meeting. We have the following comments. * default prefix vs. host language defaults The document says host-language defined set of reserved values. Such reserved values MUST translate into an IRI, just as with any other CURIE. A host language MAY declare a default prefix value, or MAY provide a mechanism for defining a default prefix value. In such a host language, when the prefix is omitted from a CURIE, the default prefix value MUST be used. Conversely, if such a language does not define a default prefix value mechanism and does not define a set of reserved values, CURIEs MUST NOT be used without a leading prefix and colon. In XForms, one candidate for use of CURIE is the appearance attribute, which is presently defined as a union of three enumeration values (minimal, compact, full) with the the set of qualified-names containing colons (qname-but-not-ncname). Given the above quote and with reference to the XHTML uses, it seems that the course would be to define our enumeration values would be to define a default prefix as "http://www.w3.org/2002/xforms/vocab#" and define minimal, compact, and full as "reserved values". We were initially confused and thought that either of these steps would be sufficient. Presumably, as an XML application, XForms has a way to define a default prefix. So we suggest normative text be added: "An XML Application SHOULD use namespace prefixes to define CURIE prefixes." However, not all XML Applcications are namespace-aware so it should not be required to use namespace prefixes to define CURIE prefixes. Also we recommend adding normative text to the effect that "XML Applications MAY define, in prose, a default prefix, which is different from their default namespace." It wasn't clear to us that reserved values may be used without prefixes; other unprefixed values are not allowed. So perhaps an example XML application that applies the above rules would be helpful. * safe_curies It was not clear that an application would be allowed to specify CURIE only and not required to include SafeCURIE. This is an important port for existing applications, because it is not a smooth transition for XForms from qname-but-not-ncname; that is, appearance="[minimal]" is not the same as the currently-specified appearance="minimal" Other existing applications may have this same problem. Therefore, we recommend an informative note that makes clear that applications can choose to use CURIEs or SafeCURIEs.