Browsers best support the window mode for the wmode parameter, also in terms of accessibility. As it is the default mode, it is acceptable to either not specify a wmode parameter altogether, or to set it explicitly to window.

The following code illustrates this rule:

<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" width="550" height="400">      <!-- Compliant -->
  <param name="movie" value="movie_name.swf" />
</object>

<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" width="550" height="400">
  <param name="movie" value="movie_name.swf" />
  <param name="wmode" value="direct" />                                                     <!-- Non-Compliant -->
</object>

<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" width="550" height="400">
  <param name="movie" value="movie_name.swf" />
  <param name="wmode" value="window" />                                                     <!-- Compliant -->
</object>

<embed src="movie_name.swf"                                                                 <!-- Compliant -->
       width="550"
       height="400"
       type="application/x-shockwave-flash"
       pluginspage="http://www.macromedia.com/go/getflashplayer" />

<embed src="movie_name.swf"
       width="550"
       height="400"
       wmode="direct"                                                                       <!-- Non-Compliant -->
       type="application/x-shockwave-flash"
       pluginspage="http://www.macromedia.com/go/getflashplayer" />

<embed src="movie_name.swf"
       width="550"
       height="400"
       wmode="window"                                                                       <!-- Compliant -->
       type="application/x-shockwave-flash"
       pluginspage="http://www.macromedia.com/go/getflashplayer" />