title: Delphi annotations
body: <p>I was looking at the implementation of the TCustomComboBoxEx object since I need to create a custom combo box in delphi and I was triying to get what I needed, when suddenly I came over this piece of code:</p>
  
  <pre><code>...
  [UIPermission(SecurityAction.LinkDemand, Window=UIPermissionWindow.AllWindows)]
  procedure TCustomComboBoxEx.CreateWnd;
  var
    ChildHandle: THandle;
    I: Integer;
    StrEnum: IEnumString;
    EditHandle: THandle;
  begin
  ...
  </code></pre>
  
  <p>What is that upon the procedure name? What is its purpose?</p>
  
  <p>Code like that work in delphi 2007 (my code needs to keep compatibility with that version)</p>