Spoiler tags are our addition to the VBB, they were not among other available tags when the VBB got installed, so maybe Harry temporarily turn the shortcut off since he's making a few changes. But... I could be wrong
Anyway, here's how to use them:
[*SPOILER][*/SPOILER]
Remove the '*' (I just put it among tags so you can see the code without it being active).
Here's how it appears without the '*' part :
We'll probably add a shortcut later to make things easier.