This is a package of RELAX-NG compact syntax schemas [RELAX-NG] suitable for validating and directed editing of OASIS Universal Business Language (UBL) [UBLTC] XML instances.

This release supports instances of UBL 2.0 [UBL 2.0] and UBL 2.1 PRD4 [UBL 2.1] simultaneously by detecting an instance's use of the <UBLVersionID> element. Though extensions are included, please review Section 5.1, “Restriction on ID/IDREF validation”.

Support for the nXML major mode [nXML] for Emacs is included.

Unzipping the package creates the base directory with one RELAX-NG compact schema for each UBL document, plus the extensions.rnc common extension schema fragment used by every main schema.

Also included is the ns-UBL-schemas.xml association between namespaces and schemas suitable for directed editing tools such as Emacs with nXML. To engage this file in nXML, add the following to the schemas.xml file of locating rules:

  <include rules="ns-UBL-schemas.xml"/>

The versions/ subdirectory has all of the individually-versioned RELAX-NG schemas, each with one modification from those published by the UBL committee: the optional UBLVersionID has a hardwired element text value being the UBL version.

The aggregate document schema titled "UBL-AllModels.rnc" allows any UBL instance to be validated with the corresponding internally-referenced RELAX-NG document model. Note, however, the magnitude of this aggregate schema may prove to exceed many processing capacities.

To engage validating or directed editing of a UBL instance, point the application to the appropriate RNC file in the base directory. Alternatively, pointing an application aware of the namespace association file will automatically engage the required RNC file from the base directory.

Each RNC file in the base directory will engage one or more modified schemas accommodating the available versions of the document type. The unmodified versions are created from using the Sun MSV RELAX-NG converter [RNGCONV] and James Clark's Trang [Trang]. The modification ensures that when the UBLVersionID element is present it must be populated with the version number of one of the available versions. Simply populating the element will ensure the remainder of the document is constrained accordingly.

For example, consider this Emacs/nXML example of an instance fragment that properly uses proposed UBL 2.1 elements:

<Invoice xmlns="urn:...>
  <cbc:UBLVersionID>2.1</cbc:UBLVersionID>
  <cbc:CustomizationID>urn:X-Crane</cbc:CustomizationID>
  <cbc:ProfileID>urn:X-Crane:SimpleInvoice</cbc:ProfileID>
  <cbc:ID>A123</cbc:ID>
  <cbc:CopyIndicator>false</cbc:CopyIndicator>
  <cbc:IssueDate>2010-03-31</cbc:IssueDate>
  <cbc:InvoiceDueDate>2010-04-30</cbc:InvoiceDueDate>
  <cbc:Note>Example invoice; not bona fide.</cbc:Note>
  <cbc:DocumentCurrencyCode>CAD</cbc:DocumentCurrencyCode>
  ...

Simply editing the version identifier to 2.0, and doing nothing else, highlights the proposed InvoiceDueDate as an unknown element in error:

<Invoice xmlns="urn:...>
  <cbc:UBLVersionID>2.0</cbc:UBLVersionID>
  <cbc:CustomizationID>urn:X-Crane</cbc:CustomizationID>
  <cbc:ProfileID>urn:X-Crane:SimpleInvoice</cbc:ProfileID>
  <cbc:ID>A123</cbc:ID>
  <cbc:CopyIndicator>false</cbc:CopyIndicator>
  <cbc:IssueDate>2010-03-31</cbc:IssueDate>
  <cbc:InvoiceDueDate>2010-04-30</cbc:InvoiceDueDate>
  <cbc:Note>Example invoice; not bona fide.</cbc:Note>
  <cbc:DocumentCurrencyCode>CAD</cbc:DocumentCurrencyCode>
  ...

If it is necessary to hardwire the validation of any particular version of a UBL schema, each version's schema is found independently in the versions/ subdirectory.

Two augmentations to UBL 2.1 are introduced in these RELAX-NG schemas:

The extensions.rnc file is delivered configured to validate an instance with the extensions found in the UBL distribution. All of the document models engage this single schema fragment in order to define the named pattern ExtenstionContentDataType.

Additional extensions are engaged in this schema fragment by following the extensions.rnc documentation of the included standardized signature extension.