title: what happens if there are two canonical tags in a page?
body: <p>I am trying to add canonical structure for articles since Google is assuming that I am duplicating contents.</p>
  
  <p>I am using symfony 1.0.6 and the success page is included in a layout and layout has its own canonical tag. I am adding another canonical tag dynamically in success page and it is resulting in multiple canonical tags.</p>
  
  <p>I cannot remove canonical tag from layout since it will be used by many other templates..</p>
  
  <p>I need to remove the canonical tag coming from layout and insert my own only for few templates ( dynamically) .</p>
  
  <p>Is it possible to achieve it.</p>