YJL

1   Single markup and link

This part is easy, just “use substitution definitions and references with the replace directive.”

[...] is |easy|_, juse use [...]

.. |easy| replace:: *easy*
.. _easy: http://example.com

2   Nesting inline markups

Nesting multiple like different text styles, it needs to manually use HTML via raw directive.

[...] like |words|_, [...]

.. _words: http://example.com
.. |words| raw:: html

  <em>different <strong>text</strong> styles</em>

I don’t think I have ever actually used this, it’s very awkward in my opinion, even more than trying to markup a partial word. I would rather choose one single markup than use both, you don’t really need to catch reader’s eye as if it were an advertisement.