title: What is the purpose of "proxy_set_header REMOTE-HOST $remote_addr"?
body: <p>I am learning to add a reverse proxy for WordPress, and in the process of referring to other people's configuration parameters, I found that someone used the following parameters in the configuration.</p>
  <pre><code>proxy_set_header REMOTE-HOST $remote_addr;
  </code></pre>
  <p>I tried to search the web to understand it, but I couldn't find any information about it. What exactly does it do, please?</p>