pound sign vs. slash as final URI delimiter

This feels like a beginner question, but after a few searches I can't find
any discussion of the issue. Let's say I have a namespace identified by the
URI http://www.example.com/pathname. To identify the name foo from that
namespace, what are the pros and cons of identifying it with a URI of
http://www.example.com/pathname/foo as opposed to
http://www.example.com/pathname#foo? The pound sign seems to more clearly
indicate "the following is a name from the namespace named up to this
point," but I see that most references to Dublin Core names (e.g.
http://purl.org/dc/elements/1.1/creator) use the slash. 

Perhaps the question is better framed without reference to syntax: is it
better for a name from a namespace to have it's own complete URI or for it
to be referenced using a fragment identifier appended to the URI for its
namespace?

thanks,

Bob