4: W3C XSD files

XML as a standard doesn't require the use of W3C XSD files (schema files). But XSD files are a very common feature that can be used by many frameworks to validate XML files.

While this library doesn't use XSD files for technical reasons (it was difficult to validate blocks of XML when dealing with very large files, and XSD files didn't play well with "streams" which are the core concepts of the library), it still includes them in its distribution.

The XSD files can be found in the resources folder of the project. There are two files for each implementation of the specifications: one for the NAACCR XML dictionaries and one for the NAACCR XML data files.

Every dictionary or data file defines the specifications it uses as a root attribute (a missing attributes means the very first specifications: 1.0). The library itself supports all the specifications that have been released so far, and so technically it supports all the versions of XSD it contains.