OK, everything I've searched several boards, including SitePoint (none of the it particularly fresh) but they all say, yup <sub> & <sup> are semantic.

... Say What?

I think its a long way from "Well, it's not deprecated yet..." to "<sup> has semantic meaning" like I've been reading. My gut says that these tags are purely presentational. Shouldn't you rather say E=mc<span class="exponent">2</span> and H<span class="molecularNumber">2</span>O.

If I'm crazy, just tell me. I'll slink back to my dev box and use <sub> and <sup> like a good little coder.