Reference: *Presentation Module at the W3C
big, small, sub, sup, i, b, tt
The Presentation Module contains elements which control the visual presentation of a page, often without having
a semantic meaning. I must admit that, with the exception of hr,
I almost never use the elements in this module, preferring to use CSS
instead, in order to separate style from content.
I do find hr useful, however, for text-only browsers (such as
*Lynx) which can display a horizontal rule as a row of dashes (for example):
it can be a handy way to separate a footer visually from the rest of the page. For graphical browsers,
there are usually better ways to make the footer content distinct and I would use
CSS to prevent display of the rule in these browsers.