Does method 'jwplayer(div).setup()' accept option 'streamer'?

Question

I try to understand how red5 works. I have looked at standard examples provided in the red5server installation directory. The 'ofla-demo' example appeared to be the most relevant. In this example index.html contains the following piece of code:

<div id='mediaspace2'>This text will be replaced</div>
<script type='text/javascript'>
  jwplayer('mediaspace2').setup({
    'flashplayer': 'player.swf',
    'file': 'skywalker.mp4',
    'streamer': 'rtmpt://localhost:5080/oflaDemo',
    'controlbar': 'bottom',
    'width': '720',
    'height': '480'
  });
</script>

When I removed the parameter 'streamer' nothing has actually changed. It kept working as it did before. I was curious about the purpose of this parameter. Looked for it in the documentation, but could not find it.

Could someone explain, why would it be included if it does not exist?