We can still mark up text that is bold or italic.

We can also have text that is somewhat smaller than the surrounding text and some that is even smaller.

Or, we can also have text that is somewhat bigger than the surrounding text and some that is even bigger.

If you like mathematics, then you may want to use superscripts or subscripts in expressions like xⁿ or P₁.

There could be times (infrequently, we hope, since it's kind of "old-fashioned") when you may want to underline something.

To indicate that something should be removed or no longer applies, you might want to strike it out or delete it. These two tags have the same effect.