title: How do I reference a documented Python function parameter using Sphinx markup?
body: <p>I'd like to reference a previously-documented function parameter elsewhere in a Python docstring.  Consider the following (admittedly completely artificial) example:</p>
  
  <pre><code>def foo(bar):
      """Perform foo action
      :param bar: The bar parameter
      """
  
      def nested():
          """Some nested function that depends on enclosing scope's bar parameter.
          I'd like to reference function foo's bar parameter here
          with a link, is that possible?"""
          return bar * bar
  
      # ...
      return nested()
  </code></pre>
  
  <p>Is there a simple way to embed a parameter reference using Sphinx markup, or will this happen automagically?</p>
  
  <p>(I'm a complete Sphinx newbie.  I've been scanning the Sphinx docs and haven't found an answer to this question, or an example demonstrating proper markup.)</p>