https://www.php.net/manual/de/domimplementation.hasfeature.php
PHP: DOMImplementation::hasFeature - Manual
Test if the DOM implementation implements a specific feature
phpmanual
https://lists.w3.org/Archives/Public/public-rdfa-wg/2010Aug/0071.html
ISSUE-43: Determine if DataParser interface needs a hasFeature("hcard") or hasFeature("hrecipe")...