By woodjr on Jan 24, 2007
Muhammad Saleem is talking about how bad URL structures can clash with social bookmarking services. Specifically, he notes that providing redundant URLs can lead to duplicate postings at sites such as Digg.
To address the situation, he advises that webmasters provide just one URL per page. That's nice in theory, but can be difficult in practice. Special needs often arise (in areas such as metrics tracking and personalization) which can best be met with varied URLs. Yes, there are a whole slew of ways to deal with such things without touching the URL. But there are also a whole slew of complicating factors (such as trying trying to monitor traffic originating outside the browser in RSS readers or emails). Sometimes one URL just isn't enough.
Fortunately, exposing multiple URLs doesn't have to mean sacrificing the idea that one of them is "primary." Just pick the primary URL and use a <link rel="bookmark" href="..." /> element to identify it (as described in the Wikipedia permalink page). Nice solution, isn't it? You get the best of both worlds--purity and pragmatism.
Unfortunately, most web sites don't include this element, and most tools don't understand it anyway. Why hasn't it gained more traction?