title: Enabling Delphi XE projects to run in earlier versions - uses naming & project options
body: <p>could anyone remind me what is the trick to allow earlier versions of Delphi (2010 for example) to accept units written in later versions which have the domain.sub-domain naming system like </p>
  
  <pre><code>    // Delphi XE2 &amp; later version (comment out for 2010 &amp; earlier):
        uses
          Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,system.Classes, Vcl.Graphics,
          Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Buttons,
          Vcl.ExtCtrls, Vcl.ComCtrls, System.Math;
  </code></pre>
  
  <p>as opposed to the D2010 &amp; earlier convention</p>
  
  <pre><code>    // Delphi 2010 &amp; earlier version (comment out for XE2 &amp; later):
        uses
          Windows, Messages, SysUtils, Variants, Classes, Graphics,
          Controls, Forms, Dialogs, StdCtrls, Buttons, ExtCtrls, ComCtrls, Math;
  </code></pre>
  
  <p>I know there's something you can do in project>options but can't find it &amp; haven't been able to find earlier forum posts on the subject..</p>