Description of whatToShow in DOMWriteFilter is unclear

The description of the whatToShow attribute in DOM3 Load and Save for 
both DOMWriterFilter and DOMBuilderFilter is unclear. For example, in 
DOMWriterFilter we find the following:

whatToShow of type unsigned long, readonly
    Tells the DOMWriter
    <http://www.w3.org/TR/DOM-Level-3-ASLS/load-save.html#LS-Interfaces-DOMWriter>
    what types of nodes to show to the filter. See NodeFilter for
    definition of the constants. The constant
    SHOW_ATTRIBUTEDOMWriterFilter. is meaningless here, attribute nodes
will never be passed to a


    For example, if I set whatToShow to NodeFilter.SHOW_ELEMENT does
    this mean that only element nodes will be output? or does it mean
    that only element nodes will be passed to the filter for further
    consideration while other kinds of nodes will be output without
    being checked through the filter? A literal reading seems to imply
    the former, but it's far from obvious. Clarification of the intent
would be appreciated.

--
Elliotte Rusty Harold