OASIS TC Open Repository: The DITA RNG Converter provides cross-platform tools for generating DITA-conforming DTD- and XSD-format versions of RELAX NG DITA grammars: document type shells, vocabulary modules, and constraint modules. It makes it as easy as possible to develop and maintain DITA grammars by allowing use of RELAX NG syntax.
Constraint modules that redeclare content models or attribute lists that themselves refer to named definitions (e.g., "univ-atts") must include those declarations in their entirety in the DTD version of the module because in the DTDs the base declarations of those parameter entities occur after the constraint module in the shell inclusion order.
This aspect of DTD syntax makes creating non-trivial constraint modules particularly tedious so this is an important feature to add.
Constraint modules that redeclare content models or attribute lists that themselves refer to named definitions (e.g., "univ-atts") must include those declarations in their entirety in the DTD version of the module because in the DTDs the base declarations of those parameter entities occur after the constraint module in the shell inclusion order.
This aspect of DTD syntax makes creating non-trivial constraint modules particularly tedious so this is an important feature to add.