On an unrelated note, I still use [+] to make the bullets in all of my posts. I found it by accident one day and it has been super useful ever since.
Come to think of it, I think Quigibo uses them in the Axe updates.
Edit: actually he uses li /li, which looks like it does the same thing.
Maybe it can made so those things only work as list things after list tags?
What I can see wrong with this, tho, is that all the keys would need an image, for every calc that's used around here
With casio calcs they're mostly the same (Casio even provides a font with them) but not so much for Ti.
That's why I was thinking of just having the defined text in there, with a border drawn around it or something.