DSDL

Document Schema Definition Languages (DSDL) is a framework within which multiple validation tasks of different types can be applied to an XML document in order to achieve more complete validation results than just the application of a single technology.

It is specified as a multi-part ISO/IEC Standard, ISO/IEC 19757. It was developed by ISO/IEC JTC1/SC34 (ISO/IEC Joint Technical Committee 1, Subcommittee 34 - Document description and processing languages).

DSDL defines a modular set of specifications for describing the document structures, data types, and data relationships in structured information resources.

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