I believe that the recommendation as it stands does precisely what you want Terry. See the codelist module template ( schema ) for an example. The iso3166:CodeType extends iso3166:CodeContentType with three fixed attributes: ID (fixed to ISO 3166 ), agencyID (fixed to 6 ), and versionID (fixed to 0.2 ). That means that the PSVI for a node of type iso3166:CodeType will always have these three attributes with those three values. So, while in the instance document, you see a nice, readable (perhaps): ... <ShippingAddress> <PostalZoneId>75075</PostalZoneId> <CountryIdentificationCode>AF</CountryIdentificationCode> ... So an XML processor (such as an XSLT stylesheet) is able to (automatically) validate the code content (in this case AF ) and the stylesheet sees not only the content, but the metadata (the ID, agencyID and versionID attributes). As for external maintenance (i.e. maintenance by the agencies -- not by UBL), again I believe that is the intent of the proposal. The purpose of having the (complex) code type wrapping the (usually simple) code content type is that the latter is usually provided by the agency. So if an agency provides something as basic as a simple type with a bunch of enumerations (like the example) then it's easy for UBL to wrap that in a complex type (adding the descriptive PSVI metadata) and viola! If the agencies decide to adopt the metadata practice too, then so much the better -- UBL won't have to do any wrappering at all. That's how I understand it anyway. Bill Burcham Sr. Software Architect, Standards and Applied Technology Sterling Commerce, Inc. 469.524.2164
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