A while ago I descovered a great BBCode tag, "Acronym", which I've been using an awful lot since, and I think it would be really useful to have it as a button.
In fact this coll little feature should be publicised as much as possible anyway so I hope people read thius and start using it all over the place.
Basically the tag does this:
[acronym=This text will appear in a tooltip box when the mouse is hovered over the underlined text]Hover your mouse over this text to see what happens.[/acronym]Hover your mouse over this text to see what happens.
The two main uses I have put this to are providing in line translation of non-English text - put the English in the acronym, around the foreign (or alien) language. Then to get the translation all the reader needs do is hover their mouse over it. I also use it for providing OOC commentary or explain a somewhat obscure reference if I think people won't get it.
I'm quite sure there are other uses... giving possible outcomes of an action, reporting a dice roll result along side the action it causes... It's just so versatile.
To make it easier to use, and because I can't spell "Acronym", please please please could we have a button for it?