Item Tooltip and Linking on Websites?Follow

I have a question.

I have noticed several guild sites using links to items from either Allakhazam or Thottbot and its a "nice" link and colored and all and on mouse-over of that link there is a tool-tip pop-up much like here on Alla or on Thott and like in-game. How is this done on an External site like my guilds PhPBB forums with HTML disabled? Is it possible and if so what code is used? Thanks!