To link to the wiki, type in [ wiki]Page name[/wiki] (without the space in the opening tag). For example, [ wiki]Special:Version[/wiki] gives Special:Version.
In addition, you can define your own link tags by using [ wiki=Page name]Link tag[/wiki]. For example, [ wiki=Special:Recentchanges]Recent changes[/wiki] gives Recent changes.
Alternatively, there are buttons for wiki and wiki= in the BBCode toolbar above the textbox when you are writing or editing posts.
Besides that, you can use spaces in page names, for example Game File Format Central, and you can link to page histories and even to the edit page via e.g. GRAFs&action=history or GRAFs&action=edit.
Now that this has been done, all links from the forum to the wiki need to be updated to use this BBCode. If you know of or run across any such links, you can update them yourself if you have the necessary priveleges, or post a link to the post with the link (sorry for being repetitious), and someone with the necessary priveleges (probably me
