Another simple method to encourage in-bound linking.
Fragment identifiers (otherwise known as 'the bit after the hash') have been around in HTML since the very beginning and offer the ability to link to a - more or less - specific point in a document. Much of the time, this facility has been used to create tables of contents at the head of documents and, slightly bizarrely, 'back to top' links. More recently, the fragment identifier has seen increasing use in the realm of accessibility, with the common use of 'skip to content' links.
The other area in which fragment identifiers are useful is when they are used for external linking, yet this is an aspect whose potential is, in many cases, yet to be reached. What am I talking about here? Well, take that previous link (it's bold, by the way) as an example; here's the URL:
http://www.w3.org/History/19921103-hypertext/hypertext/WWW/MarkUp/Tags.html#13
Let's ignore the choice of the slightly cryptic '13' for the moment, and concentrate on where we end up in the document. Keen readers will have noticed that the target point is actually the 'HREF' header, not the 'NAME' header to which I actually wished to refer. Why? Because the HREF element (dt) actually has an id attribute, unlike the NAME.
OK, that's all rather pedantic and hardly the end of the world, but the problem is magnified when you consider long articles with very few 'target points' at all. While the layout elements of the page are well id'd (presumably, mainly due to CSS requirements), the entire body copy is in an 'articletext' id'd div, with no granularity below that. Don't get me wrong, a list apart is an excellent source of high-quality, influential content, but despite - and possibly because - of that, their lack of regular and frequent id'd elements infuriates me.
The breadcrumb metaphor is already overloaded (hierarchy, browser history) and I'm about to add a third usage, so please forgive me. Like Hansel and Gretal's morsels, the id attribute should be thought of as a placeholder: drop one whenever you - or, more importantly, someone else - might want to get back 'here'.
Every heading should have an id'd header. Every table, list, blockquote, and address should really be identifiable, not just because of the traditional fragment identifier usage, but also because of uses that were never originally envisaged. The age of ajax is, one day, a-coming, and properly identified content is a must.
Whatever the other arguments, just bear this one in mind: id'ing your content will only serve to encourage others to link to it, and that must be a good thing, right?