Mild bafflement of the day

Some items in WoW are classified as "unique", meaning that a character can only ever own one; if they already have it, they can't get a second one. Other items are "unique-equipped": you can own as many as you have room for, but you can't wear more than one at a time. This is common for rings (you get two), trinkets (ditto), and certain gems.

My mage has a unique-equipped /necklace/.

There is one necklace slot. It is not possible to wear two necklaces, unique or otherwise. So why the freaking flying ferret-arse did they bother making it unique-equipped?

(Unless Cataclysm will come with all sorts of jewelry slots: up to six earrings, a nose ring, up to ten necklaces, up to twenty bracelets, up to ten rings, oh and also toe rings.)