The BBCode reference menu seems to be missing from the right hand side of the article edit menu, for all articles. It's typically located next to the 'Need any help?' tooltip, under the 'Open Advanced Tools & Options' tab. Attached is a screenshot of what I'm able to see.
Simply open the edit menu for an article and the option will be missing; I've tried this on both Opera and Firefox for several articles.
Hey there - I can see that you are using the WYSIWYG editor - which means that you should not be using any advanced BBCode. This is the reason we hid it for users that do not use the advanced editor (it will be propagating across the whole website soon) Feel free to message me here with any other questions.
Oh, that's an odd change, but I can understand why it's being made, I guess. I prefer the editor layout of WYSIWYG, as it's not as blocky/clunky and is more streamlined than the advanced editor. I was adding the more complex BBCode in the 'View Source' toggle for formatting purposes, though the more common ones, such as indent, I knew by heart. I suppose if that is a change that will be going through I will just have to grab BBCodes and put them in a note someplace for my own reference. ♥