What is the name space for DataHandler?

[V D]

When generating a wsdl from java with attachment (DataHandler), I see this:
<wsdl:part name="in0" type="apachesoap:DataHandler"/>
in the message declaration.
Is this "apachesoap" namespace not following standard?  What is the 
standard way of doing this?  Would this WSDL be a problem if running 
under other library/platform than Axis?

Thanks,
Vh.