When parsing a beans.xml, and entering /beans/scan, the XML stream parser accepts a number of namespaces defined in org.jboss.weld.xml.BeansXmlStreamParser.SCANNING_URIS.

When a matching element is found, execution will jump to parseScan. This method in turn will continue until the expression isEnd(event, SCAN) is true. isEnd(XMLEvent, String) will call isEnd(event, name, JAVAEE_URIS).

SCANNING_URIS is a super set of JAVAEE_URIS with the additional entry http://jboss.org/schema/weld/beans_; it is thus possible to start parsing a scan element, but if using the _weld namespace, parsing will not stop until the end of the stream is reached. Because of the forgiving nature of the parser, no error messages will be generated.