[In another thread, in IMHO, I believe, the OP placed a brief message at the top of his screen, enclosed in brackets. Not as a VB code, but just to separate it. On mouseover, the enclosed text did not appear. Could this be a way to hide spoiler type information?]
Does this show up in Mouseover?
[ETA: any VB code included in the bracketted text negates the effect for the rest of the section, including spoilers. But it could be used for those threads where an expository section is needed for the whole post, but isn’t on point to attract people in from a mouseover.
The workaround to this is to put the mouseover-killing [ just inside the spoiler tag, instead of outside it. Then, as long as you don’t bold or change the font or anything in the spoiler, it’ll be invisible both inside and outside the thread, as it should be.
I mentioned it about a year ago (the secret word is ‘Goatfelcher’). I’m guessing the trick isn’t more widely used simply because not many people know about it. I’ve only ever seen it mentioned in ATMB test threads, and for some reason quite a few Dopers just aren’t that interested in those threads. They’re missing out if you ask me.