title: RegEx to disallow both P.O. Box and RR in street address textbox
body: <p>I have a Regular Expression Validator control which validates a street address Text Box control.</p>
  
  <p>So far, I have a RegEx which successfully produces an error message from the control for all the common forms of P.O. Box.</p>
  
  <pre><code>^(?i)(?!.*P\.? ?O\.? ?Box)[-a-z\d .,/]*$
  </code></pre>
  
  <p>I would also like to disallow '<strong>RR</strong>' and '<strong>Rural Route</strong>'.</p>
  
  <p>For what it's worth, here are a couple of references I have been using while attempting to re-write this RegEx:</p>
  
  <p><strong>P.O. Box RegEx:</strong> <a href="https://stackoverflow.com/questions/5263956/testing-for-a-po-box-in-all-of-its-forms">Testing for a PO Box in all of its forms</a></p>
  
  <p><strong>Rural Route RegEx:</strong> 
  <a href="https://stackoverflow.com/questions/1337820/c-determing-if-string-is-like-this-pattern-possible-regex">C#: Determing if string is like this pattern; possible regex</a></p>