https://www.nist.gov/publications/xinclude-test-suite-version-2-xml-core-working-group
XInclude Test Suite Version 2, XML Core Working Group | NIST
Feb 17, 2017 - The goal of this document is to help W3C editors write better specifications, by making a specification easier to interpret without ambiguity and clearer as to
xml core working grouptest suiteversionnist