Should there be a standard way to give credit in a weblog entry?

A lot of smart people have been thinking about the data model of a weblog entry (going back to the weblog profile for RSS initiative that stalled out and partly led to the Pie process), and particularly what are the likely meanings of the link element, which can be (as originally invisioned) a link from a description to a full item, or (as Blogger’s link field and bookmarklets imply) a link to an external resource that the weblog entry comments on, or (as is commonly generated by Movable Type) a permalink for the entry, regardless of whether a summary, excerpt, or complete body text have been packed into the description field.
Those are the three most likely key links in a blog entry, and they are sometimes the same thing, especially when there is no external resource. Including links in an entry body doesn’t inherently populate the link feed, although in theory a blog tool could grab the first anchor href, if any, and use that as the default link, if not overriden. Instead, the default seems to be the permalink, with the option – in some tools – over overriding with an external-resource link.
During the RSS 2.0 process, a “b link” module was proposed by Mark Pilgrim, as a kind of “the blog I’m currently reading or recommending” and adopted into the spec by Dave Winer, but it didn’t really catch on, being a sort of off-the-cuff vanity item.
There’s another kind of link, however, that I think most of us have been overlooking, although its presence in the blog world is nerly ubiquitous, under a numer of different names. What I’m talking back is a link that credits the source of an item. Like many people in the blogosphere, I consider it good netiquette to include a link to the source of an item, particularly when the resource isn’t at the time generally available from many sources. Radio, for example, automatically captures that link when you post from its aggregator.
I think this “via link” or “hat tip” should be acknowledged as a well understood, if optional / conditional (only if there is a key source) field in the weblog data model. Not only is it “nice,” it would actually make it easier to trace the spread of ideas, a kind of reverse tracking-back.