Setting WARN_BAD_NAME when reading RDF/XML file has no effect

[Mark Anderson]

I'm reading a RDF/XML file that results in a large number of warnings such
as

WARN  Feb 21 11:13:05.966 2803 [main] org.apache.jena.riot [line: 16610,
col: 45] {W108} Not an XML Name: '883553724818784620'

My understanding was that I could ignore these by reading the RDF/XML as
follows:

Model model = ModelFactory.createDefaultModel();
RDFReader reader = model.getReader();
reader.setProperty("WARN_BAD_NAME", "EM_IGNORE");
reader.read(model, inputStream, base);

However, setting the property has no impact. What options to I need to set
to ignore these warnings?

Thanks,
Mark