What do you call it when you pass a parameter to the next parameter
<p>I notice a lot of code where people do something like:</p>

<pre><code>myClass.someMethod(something here, $1);
</code></pre>

<p>The $1 is picking up a value from "something here"?</p>

<p>What is this known as? I can't seem to find it anywhere? But this step, process is used in cases with regex quite a bit..</p>
