<sup> text </sup>tells the browser to render the text as a "superscript" as shown below.
Pythagoras' Theorem states x2 = y2 + z2 where x is the hypotenuse and y,z the lengths of the two other sides of a right angle triangle.
Here's the HTML for the equation above
<sup>?2</sup> = y<sup>2</sup> + z<sup>2</sup>The effects of including futher <sup> tags within superscript text are unpredicatable - but here goes
22 = 4
222 = 16
2222 = 65536
22222 = A very big number
Browsers
NN seemed capable of indefinite superscripting.
IE3 could only manage two levels of superscript and
IE4 and MOS3 could only manage a single level.
OP2 and ARA ignored the tag.