Along with recognizing and using a real abbreviation (see my .sig), I
think a sign of literacy is proper use of subscripts and superscripts. All
too often, I see such inexcusable barbarisms as "1012", for ten to the
12th power, and "H2O". While ASCII* has no provisions for subs and sups,
HTML does, and the latter are truly easy to use. </rant> Perhaps it's the
tragic disrepute (or is it social unacceptability?) that science and math.
have among much of the US public, combined with extreme widespread
ignorance about basic chemistry that makes these in-line forms acceptable.
</rant>

* More accurately, I mean any scheme for composing and representing text
that doesn't provide for subs and sups. Other than the likes of ² , ³ , ª
and º, alphanumeric character sets don't seem in general to have what's
needed unless one goes to Unicode or a "competitor".

Anyhow, the isolated caret [^] (or the letter E, for "exponent") can help
a lot when working with plain text that doesn't include provisions for
general sub asd superscripting, as in "10^12" or "10e12". However, a
concise way of indicating a subscript has seemed problematic until
recently. I haven't really tried to find the various markups for
subscripts, but had seen [.sub.] somewhere, and risked annoying the
denizens of howthingswork@yahoogroups.com, where I seem to spend about 3%,
maybe 5% of my life; we discuss all sorts of technical and scientific
stuff (as well as some linguistics and even writing systems, just a bit)
over there. However, "H.sub.2O" seems like a bit of an imposition. Markup
spoils smooth readability.

Well, it's hardly worth all that introduction, but if we don't have an
inverted caret, and a [v] probably doesn't have the right implications,
somebody chose to use [_], a bit too low to be a lowered dash (or is it?),
but the suggestion of something either low, or being moved down, seemed
sensible. "H_2O" was the sort of notation used in a formal academic paper
I came across recently. It does seem that a different markup would be
needed to indicate more than one consecutive subscripted character,
though. I like it. :)

Best regards, not middling..

--
Nicholas Bodley /*|*\ Waltham, Mass. (Not "MA")
Science education in Kansas: The water in
the oceans does not fall off the edges of the
Earth because it is God's will that it not do so.