In reStructuredText, how do I use emphasis and superscript at the same time?

Question

The following piece of reStructuredText does not give the result I expect.

*:sup:`superscript`*

Expected result: ^superscript

Actual result: :sup:`superscript`

The reason why it is happening is clear (reST text roles cannot be nested), however how can I obtain the expected result?

Answer 1

You can use substitution:

The chemical formula for pure water is |H2O|.

.. |H2O| replace:: H\ :sub:`2`\ O

See the reStructuredText spec for further information on character-level markup and the substitution mechanism.

Answer 2

As specified in a FAQ, this is not currently possible without using the raw directive or without using a custom, ad-hoc directive.