To use a goban (game-board) in the forums, private messages or move messages, you should use the goban editor to edit the shape, then copy the raw-format with the <igoban>-tag to the target location you want to have it placed without saving it as shape (which is only needed when you want to create a shape-game). Use "Preview" on the target page to check if it's correctly formatted before you submit it.
 
The full syntax of gobans is listed on the goban editor page. Also see: Are there examples of game boards?