Dunno about the others, {{sup|...}} behaves exactly as you describe,
on en at least.
Really?!? I'm gonna hafta' dig deepa' wid this stuff :)
One possible benefit of such templates is that they become documented
in a predictable place. Simply search for template:sup and you'll find
what it does, and when to and not to use it. How would you find out
what <sup> did?
Same way I learned just about every other tag/directive/class, etc.
I read a book (or two or seven). I'm a great believer in reading then
doing, though there is no experience quite like the one afforded by
raw empiricalism (warts and all). There is no better teacher than
making a mistake and no better student that the one that admits the
error and learns from it. As Piet Hein said (and I paraphrase)
"The secret to success is to err and err and err, but less and less
and less."
But that's just me.
r