A second attribute should be added to <ref> and <references> tags, perhaps
"group". Ideal behavior would be
<references group="blah_group" />
Now, what in heaven's name would the point be of having multiple incompatible
numbers on the same page? Look at, say,
http://en.wikipedia.org/wiki/Comparison_of_operating_systems. Each section has
its own notes, which are for aesthetic purposes contained within their own
sections rather than being all at the end.