title: Add constraint to route to exclude certain keyword
body: <p>I am using Rails and I want to use contraint in route to exclude that route if keyword "incident" is anywhere in the url. </p>
  
  <p>I am using rails3.</p>
  
  <p>Here is my existing routes.</p>
  
  <pre><code>match ':arg', :to =&gt; "devices#show", :constraints =&gt; {:arg =&gt; /???/} 
  </code></pre>
  
  <p>I need to put something in constraints so that it does not match if word "incident" is there.</p>
  
  <p>Thanks </p>