DTDSchemadefinition

DTDSchemadefinition is a formal, machine-readable specification intended to describe the structure and constraints of XML Document Type Definitions (DTDs). It acts as a meta-schema that defines how a DTD can be represented in a standardized schema language, enabling consistent validation, generation, and interoperability among tools that create or process DTDs.

The scope of DTDSchemadefinition includes the core constructs of DTDs such as element declarations, attribute list declarations, entity declarations, and notation declarations. It provides a formal grammar for describing content models (child elements, sequences, choices, and occurrence indicators), as well as the relationships between internal and external subsets, parameter entities, and general entities. By normalizing these concepts, the DTDSchemadefinition aims to reduce ambiguity in how DTDs are authored and interpreted by different software systems.

In terms of representation, a DTDSchemadefinition typically specifies a schema language or a descriptive meta-model that can be encoded in a machine-readable form, such as JSON or XML, and versioned for compatibility. It defines metadata for elements like element names, content models, attribute types and defaults, entity scopes, and the permissible structural constraints within a DTD.

Applications of DTDSchemadefinition include validating DTDs within editors and validators, guiding code generation for DTDs, and enabling tooling to reason about DTD compatibility and transformation. It exists as a conceptual framework to standardize how DTDs are described, rather than a widely adopted, separate standard. See also XML, DTD, XML Schema, and related schema-definition efforts.