http://en.wikipedia.org/wiki/Permalink
A permalink is a URL that points to a specific blogging entry even after the entry has passed from the front page into the blog archives. Because a permalink remains unchanged indefinitely, its use avoids link rot. Most modern weblogging and content-syndication software systems, including Wordpress, Movable Type, LiveJournal, RapidWeaver, Pivot and Blogger, support such links. Other types of websites use permalinks, too, but the term itself is most common within the blogosphere. Permalink is a portmanteau word made from permanent link. Permalinks are often simply stated so as to be human-readable.
