title: iframe's content and visibility based on a user-agent
body: <p>So, I am making my own page <em>(which is going to be an embedded <code>&lt;iframe&gt;</code> for other websites later)</em>. The page simply is an advertisement banner.</p>
  <p>I want the banner to be visible for mobile users only, and the content has to different for Android and/or iOS users <em>(by tracking is it Safari browser for example)</em>.</p>
  <p>I've never had an experience with the <code>&lt;iframe&gt;</code> before, so I don't really understand how the data works with it. Can it be configured on the side of the iframe (my page, the banner's source code)? Or it has to be configured on the website, which is using the <code>&lt;iframe&gt;</code>?</p>