With the help of the Most Enlightened (thanks!) (and some research on my part), we now have new link tags available. Each searches a certain site for the value you provide and returns a list of hits:
[jargon://] searches the Jargon file hosted at the University of Amsterdam.
Examples: meme, "You're a Nazi!", "Don't do this."
(I chose this one because I can get to it through the web filtering software I have to deal with at work. Folks have posted links to other copies of the Jargon file, but many of those are blocked by that software.)
[kobe://] is an alternate for the [cpan://] tag; it searches the CPAN mirror at the University of Winnipeg for a given module or distribution. It's named after the maintainer of that site.
Examples: sendmail, lwp, Here's an easy way to install CPAN modules.
(It was chosen because I've found [cpan://] to be slow from time to time and use this one more often than not.)
[perldoc://] searches perldoc. The idea here is to provide a way of linking to current Perl documentation.
Examples: unlink, A Cookbook, "How do I send email from Perl?"
(This was based on a recent conversation.)
Again, these tags only provide the search results, so they're not as specific as linking directly to a given document. However, I hope they'll prove at least as useful as other tags that've been added over time.
Update: Owing to popular demand, we've added [pad://] as a shortcut to a user's scratch pad.
Please note that this behaves slightly differently if you do not enter a title parameter. If, for example, you type [pad://footpad], the result is "footpad's scratchpad".
If you enter a title, it behaves like the other link tags, e.g. "Check this out."
Update #2: Thanks to the tireless (and a little help from me), the documentation has been updated. (P.S. Thanks for the help, tye.)